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  1. Oct 10, 2013 #51

    marcus

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    The title of the talk Derek Wise is scheduled to give on Tuesday (in 5 days from now) has been posted. Here's the current ILQGS schedule as it stands so far.

    Code (Text):
    DATE    Seminar Title                                    Speaker      Institution
    Sep 03 [B]Multiymplectic effective General Boundary Field Theory[/B] J.Zapata   Morelia
    Sep 17 [B]Thermality of spherical causal domains–entanglement spectrum[/B] H.Haggard Marseille
    Oct 01 [B]BH entropy from LQG: higher dim. and gen. theories[/B] N.Bodendorfer  PennState
    Oct 15 [B]Holographic SR: observer space from conformal geometry[/B] Derek Wise Erlangen
    Oct 29 TBA                                       Asieh Karami    Morelia
    Nov 12 [B]What can we learn from shape dynamics?[/B]        Tim Koslowski     NewBrunswick
    Nov 26 TBA                                       Johannes Thürigen PotsdamAEI 
    Dec 10 TBA                                       Saeed Rastgoo   Morelia
    http://relativity.phys.lsu.edu/ilqgs/

    http://arxiv.org/abs/1305.3258
    Holographic Special Relativity
    Derek K. Wise
    (Submitted on 14 May 2013)
    We reinterpret special relativity, or more precisely its de Sitter deformation, in terms of 3d conformal geometry, as opposed to (3+1)d spacetime geometry. ...
    ... We conjecture a relationship between this kind of "holographic relativity" and the "shape dynamics" proposal of Barbour and collaborators, in which conformal space takes the place of spacetime in general relativity. We also briefly survey related pictures of observer space, including the AdS analog and a representation related to twistor theory.
    17 pages, 5 illustrations
     
    Last edited: Oct 10, 2013
  2. Oct 14, 2013 #52

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    I found this:

    http://www.claymath.org/workshops/CCC/ [Broken]
     
    Last edited by a moderator: May 6, 2017
  3. Oct 14, 2013 #53

    marcus

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    Interesting find! Here is the poster, with an elaborate drawing by Penrose illustrating his CCC idea:
    http://www.claymath.org/workshops/CCC/CCCposter.jpg [Broken]
    You can click on it to enlarge it, making it more legible.

    I see that among those on the discussion panel and/or giving talks were Kris Meissner (Warsaw), George Ellis (Capetown), Ted Newman (Pittsburg). Meissner posted a paper in July presenting new statistical evidence of circular ripples in the CMB that might have emanated from events in prior aeon, thus supporting the CCC conjecture. The site has abstracts for some of the talks. Here is a partial list of titles:

    9:00 Roger Penrose On CCC's motivations, equations, observational implications, and future research
    10:00 Vahe Gurzadyan Positive lambda, the 2nd law and observations
    11:30 Krzysztof Meissner
    2:00 Paul Tod The equations of CCC
    3:00 Michael Eastwood Twistors, tractors, and conformally invariant operators
    4:30 Rod Gover Klein, Poincaré, and geometry at infinity

    9:00 Gabriele Veneziano A bouncing cosmology from string theory's new symmetries?
    10:00 Kostas Skenderis Holography and the very early universe
    11:30 Tsou Sheung Tsun A theory of Fermion masses and mixing
    2:00 Helmut Friedrich Existence and asymptotic behaviour of space-time with positive lambda
    3:00 Lars Andersson
    4:30 Tim Adamo Gravity in twistor space

    9:00 Claude LeBrun
    10:00 Jörg Frauendiener
    11:30 Laszlo Szabados On the total mass of closed universes with positive cosmological constant
    2:00 Neil Turok
    3:00 George Ellis Indications that gravity is essentially a conformal theory
     
    Last edited by a moderator: May 6, 2017
  4. Jan 14, 2014 #54

    marcus

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    This semester's schedule for the International LQG Seminar was posted today.
    To follow the ILQGS series, go here:
    http://relativity.phys.lsu.edu/ilqgs/
    Links to audio and to slides PDF usually appear there around the time that the online seminar is scheduled to be given. Get the slides on a separate window before you start the audio, so you will be able to scroll through the slides along with the speaker.
    ==quote==
    ILQGS SEMINAR SCHEDULE
    SPRING 2014
    Code (Text):

    1/21  [B]Matter matters in asymptotically safe quantum gravity[/B]  P. Dona (Sissa)
    2/4   TBA                    B. Dittrich (Perimeter)
    2/18  TBA                    S. Steinhaus (Perimeter)
    3/4  [B]Simplicity constraints in spin foam models[/B]  M. Geiller, S. Speziale (PSU,Marseille)
    3/18 [B]S-matrices for General Boundary QFT on Anti de Sitter spacetime[/B]  M. Dohse (Morelia)
    4/1  [B]Continuum limit and renormalization[/B]      L. Freidel (Perimeter)
    4/15 [B] Linking canonical and covariant LQG[/B]     A. Zipfel (Erlangen)
    4/29  [B]LQC and the very early universe[/B] I.Agullo, A.Barrau, G.Mena (LSU, Grenoble, Madrid)
    5/13  [B]Hawking radiation in LQG[/B]            J. Pullin (LSU)
     
    ==endquote==
     
    Last edited: Jan 14, 2014
  5. Jan 22, 2014 #55

    marcus

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    ILQGS SEMINAR SCHEDULE (update)
    SPRING 2014
    Code (Text):

    1/21  [B]Matter matters in asymptotically safe quantum gravity[/B]  P. Dona (Sissa)
    2/4   [B]A new vacuum for loop quantum gravity[/B]      B. Dittrich (Perimeter)
    2/18 [B]Quantum group spin nets:refinement & relation to spin foam[/B] S. Steinhaus (Perimeter)
    3/4  [B]Simplicity constraints in spin foam models[/B]  M. Geiller, S. Speziale (PSU,Marseille)
    3/18 [B]S-matrices for General Boundary QFT on Anti de Sitter spacetime[/B]  M. Dohse (Morelia)
    4/1  [B]Continuum limit and renormalization[/B]      L. Freidel (Perimeter)
    4/15 [B] Linking canonical and covariant LQG[/B]     A. Zipfel (Erlangen)
    4/29  [B]LQC and the very early universe[/B] I.Agullo, A.Barrau, G.Mena (LSU, Grenoble, Madrid)
    5/13  [B]Hawking radiation in LQG[/B]            J. Pullin (LSU)
     
    Links to audio and slides PDF posted here:
    http://relativity.phys.lsu.edu/ilqgs/
    E.g. for the 21 Jan talk by Pietro Donà
    http://relativity.phys.lsu.edu/ilqgs/dona012114.pdf
    http://relativity.phys.lsu.edu/ilqgs/dona012114.wav

    Hopefully the slides PDF for the 4 Feb talk by Bianca Dittrich will be posted well in advance of the talk so one can get an idea of the topic A new vacuum for loop quantum gravity ahead of time. If and when that happens, the link might be:
    http://relativity.phys.lsu.edu/ilqgs/dittrich020414.pdf
     
    Last edited: Jan 22, 2014
  6. Feb 20, 2014 #56

    marcus

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    Re the previous post, both slides and audio are online for all three of the ILQGS talks that have been given so far this semester. The link that works for me, for the audio of Steinhaus' talk is:
    http://relativity.phys.lsu.edu/ilqgs/steinhaus021814.wav
    although it currently does not appear in the main menu at http://relativity.phys.lsu.edu/ilqgs/

    Here are some QG and QG-related workshops, schools, or conferences scheduled for this year:

    June http://www.centrovolta.it/sigrav2014/ [Broken]
    Gravity and the Quantum

    July http://ift.uni.wroc.pl/~mborn33/
    Noncommutative geometry, quantum symmetries and quantum gravity

    September http://www.sissa.it/app/esqg2014/
    Experimental Search for Quantum Gravity

    The June 1-6 SIGRAV school, "Gravity and the Quantum", at a villa on the Lago di Como in Northern Italy sounds nice. Here are the introductory/survey courses being offered

    QUANTUM COSMOLOGY Abhay Ashtekar
    NON-COMMUTATIVE GEOMETRY AND QUANTUM GRAVITY John Barrett
    BLACK HOLES Eugenio Bianchi
    QUANTUM SPACE Laurent Freidel
    ASYMPTOTIC SAFETY Roberto Percacci
    COVARIANT LOOP QUANTUM GRAVITY Carlo Rovelli

    Here are some photos of the Villa del Grumello where it is being held and the Lake Como surroundings:
    http://www.villadelgrumello.it
     
    Last edited by a moderator: May 6, 2017
  7. Feb 24, 2014 #57

    marcus

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    Princeton IAS will hold a one-week school focused on String Theory the week of June 16-20. This is part of the PiTP (Prospects in Theoretical Physics) annual series, aimed primarily at advanced graduate students and postdocs.
    Here is the PiTP 2014 home page:
    https://pitp2014.ias.edu

    A partial list of topics to be covered:
    "Application of AdS/CFT" (Steven Gubser, Princeton University)
    "Introduction to Higher Spins" (Simone Giombi, Princeton University)
    "Introduction to Topological String Theory" (Hirosi Ooguri, California Institute of Technology)
    "String Compactification" (To Be Announced)
    "Super-Symmetric Quantum Field Theories" (Nathan Seiberg, Institute for Advanced Study)

    Other lecturers will be: Nima Arkani-Hamed (Institute for Advanced Study), Igor Klebanov (Princeton University), Juan Maldacena (Institute for Advanced Study), Alexander Polyakov (Princeton University), Herman Verlinde (Princeton University), and Edward Witten (Institute for Advanced Study).

    The annual Strings conference will be held the following week June 23-27
    http://physics.princeton.edu/strings2014/Home.shtml

    Strings 2015 will be held in Bangalore, India.
     
  8. Feb 26, 2014 #58

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    Experimental Search for Quantum Gravity workshop

    1-5 September SISSA/ISA Italy

    http://www.sissa.it/app/esqg2014/

    Maurizio Gasperini (University of Bari)
    Sabine Hossenfelder (NORDITA, Stockholm)
    Stefano Liberati (SISSA)
    Roberto Percacci (SISSA)
    Lee Smolin (PI, Waterloo)
    Stefano Liberati (SISSA)
    Roberto Percacci (SISSA)
    Alessio Belenchia (SISSA)
    Dionigi Benincasa (SISSA)
    Arif Mohd (SISSA)
    Alejandro Castedo (SISSA)
    David Marzocca (SISSA)
    Bethan Cropp (SISSA)
     
  9. Feb 26, 2014 #59

    marcus

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    What I see at the ESQG workshop website is a list of confirmed speakers different from what just MTd2 posted:
    ==quote==
    Talks

    Confirmed speakers

    Name--------- Institution
    Giovanni Amelino-Camelia Sapienza, Rome
    Massimo Cerdonio INFN, Padua
    John Donoghue University of Massachusetts, Amherst
    Astrid Eichhorn Perimeter Institute, Waterloo
    Jonathan Granot Open University of Israel
    John Kelley IMAPP, Radboud University, Nijmegen
    Jerzy Kowalski-Glickman University of Wroclaw
    Joao Magueijo Imperial College, London
    David Mattingly University of New Hampshire
    Jakub Mielczarek Jagiellonian University, Crakow
    Igor Pikovski Vienna Center for Quantum Science and Technology
    Floyd Stecker NASA - Goddard Space Flight Center
    ==endquote==

     
  10. Apr 12, 2014 #60

    marcus

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    Great talks on YouTube from 10-12 June 2013 conference at Oxford
    on Cosmology and Quantum Foundations
    for example:


    and



    when these come up there will be also a menu of other talks at the same conference.

    Thanks to Fuzzyfelt for putting me onto these links!
     
    Last edited by a moderator: Sep 25, 2014
  11. Jun 8, 2014 #61

    marcus

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    The fourth workshop on the Experimental Search for Quantum Gravity (ESQG) will be held in Trieste on 1-5 September
    http://www.sissa.it/app/esqg2014/
    Since it's still 3 months off, titles of talks have not yet been announced. Here's the list of invited speakers:
    Code (Text):

    Stephon Alexander   Dartmouth
    Giovanni Amelino-Camelia    Sapienza, Rome
    Massimo Cerdonio    INFN - Padua
    Astrid Eichhorn         Perimeter Institute, Waterloo
    Agnes Ferte         Institut d'Astrophysique Spatiale
    Julien Grain            Institut d'Astrophysique Spatiale
    Jonathan Granot         Open University of Israel
    Giulia Gubitosi         Sapienza, University of Rome
    Brian Keating           University of California, San Diego
    John Kelley         IMAPP, Radboud University, Nijmegen
    Jerzy Kowalski-Glikman  University of Wroclaw
    Joao Magueijo           Imperial College, London
    David Mattingly         University of New Hampshire
    Jakub Mielczarek    Jagiellonian University, Crakow
    Jonathan Miller         Universidad Tecnica Federico Santa Maria
    Daniele Oriti           Albert Einstein Institute
    Igor Pikovski           Vienna Center for Quantum Science and Technology
    Carlo Rovelli           Aix-Marseille University
    Floyd Stecker           NASA - Goddard Space Flight Center
    The purpose of the workshop is to bring together experimentalists, theoreticians, and phenomenologists interested in possible tests probing the quantum/discrete structure of spacetime. There will be a number of rather focussed talks discussing possible phenomenological tests of quantum gravity and proposing some new ideas in this direction.
    ===============
    Strings 2014 is scheduled for 23-27 June at Princeton
    http://physics.princeton.edu/strings2014/Invited_speakers.shtml
    The list of invited speakers has 74 names.
    The titles of the talks have not been posted as yet.
    ================

    The 2014 SIGRAV school "Gravity and the Quantum" was just held 1-6 June at Villa Grumello on Lake Como in Italy.
    http://www.centrovolta.it/sigrav2014 [Broken]
    Here's a list of the six courses given at the school:

    QUANTUM COSMOLOGY Abhay Ashtekar
    NON-COMMUTATIVE GEOMETRY AND QUANTUM GRAVITY John Barrett
    BLACK HOLES Eugenio Bianchi
    QUANTUM SPACE Laurent Freidel
    ASYMPTOTIC SAFETY Roberto Percacci
    COVARIANT LOOP QUANTUM GRAVITY Carlo Rovelli

    I understand each course consisted of a series of lectures given on different days. Ashtekar's was a series of five. Links to slides for some of the talks have been posted.
    =================
     
    Last edited by a moderator: May 6, 2017
  12. Jun 14, 2014 #62

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    Talk titles for the Strings 2014 conference speaker list were posted today, about 9 days in advance of the conference. Here's the link:
    http://physics.princeton.edu/strings2014/Talk_titles.shtml
    Name Title
    Code (Text):
    Anderson    Hidden geometry in heterotic string and F-theory compactifications
    Basso       Scattering amplitudes at strong coupling beyond the area paradigm
    Baumann     B-modes and the Nature of Inflation
    Bizon       Gravitational turbulent instability of AdS5
    de Boer     The entropy of a hole in space-time
    Bousso      A Proof of the Covariant Bound
    Cachazo     Scattering Equations   
    Casini      Entropy and Energy on null surfaces
    Cheng       Umbral Moonshine and String Theory
    Chesler     A holographic perspective on the Kibble-Zurek mechanism
    Conlon  Moduli, 0.1-1 keV Cosmic Axion Background and the Galaxy Cluster Soft Excess   
    Cordova     Toda CFT from Six Dimensions
    Cremonini   Probing the structure of quantum phases of matter with holography
    Dabholkar   Quantum Black Holes and Quantum Holography 
    Dolan       Amplitudes and the Scattering Equations, Proofs and Polynomials
    Erdmenger   Applications of AdS/CFT to high energy and condensed matter physics*
    Esole       Singularities and Gauge Theory Phases
    Freedman    Precision Tests of the AdS/CFT Correspondence  
    Gaiotto     Topological order in N=1 Super Yang Mills theory
    Gauntlett   Holographic Lattices, Metals and Insulators
    Gomis   Sphere Partition Functions, the Zamolodchikov Metric and Surface Operators 
    Gopakumar   From Higher Spins to Strings   
    Graham      New methods for discovering light fields
    Green       Visionary
    Gromov      Quantum spectral curve and AdS/CFT spectral problem
    Gross       Visionary
    Guica       A toy model for the Kerr/CFT correspondence
    Hanada      Monte Carlo approach to string/M-theory
    Hellerman   String Theory of the Regge Intercept
    Hubeny      Holographic Entanglement
    Kachru      Mock Modular Moonshine for M22 and M23
    Klevers     Recent Progress on the Abelian Sector of F-theory
    Komargodski A Cardy-like formula in four dimensions
    Kovac       Detection of B-mode Polarization at Degree Angular Scales with BICEP2
    Kutasov     ADE N=1 SUSY Dynamics
    Lee,Sungjay New Exact Results on D-branes and Orientifolds in Calabi Yau Spaces
    Lee,Sangmin Scattering amplitudes in three dimensions
    Leigh       The Exact are normalization Group and Higher Spin Holography   
    Liu     Entanglement Tsunami
    Mafra       The closed-string 3-loop amplitude 
    Maldacena   Visionary  
    Marchesano  F-term axion monodromy inflation
    Marino      Non-perturbative effects in M-theory   
    Minahan     Three-point correlators from string theory amplitudes
    Moore       Visionary  
    Murugan     Meromorphic functions and the topology of giants   
    Neitzke     A smooth R3 index for N=2 theories in four dimensions
    Nekrasov Nonperturbative Dyson-Schwinger identities in gauge theories and sigma models
    Papadodimas The black hole interior in AdS/CFT 
    Polchinski  Black Hole Information: Spacetime versus Quantum Mechanics*
    van Raamsdonk   Gravitation from Entanglement
    Raju        State dependent operators and the information paradox
    Rastelli    The Superconformal Bootstrap
    Sen         Mass renormalization and vacuum shift in string theory
    Silverstein The powers of monodromy
    Simmons-Duffin  Bootstrapping the 3d Ising Model
    Staudacher  N=4 Scattering Amplitudes and the Regularized Graßmannian
    Steinhardt  TBA
    Stieberger  Unity of tree–level superstring amplitudes
    Strominger  Visionary
    Sundrum     BTZ/CFT
    Tachikawa   Recent advances in SUSY*
    Takayanagi  Quantum Entanglement and Local Operators
    Tomasiello  New gravity duals for higher-dimensional superconformal theories
    Tonni       Entanglement negativity in conformal field theory  
    Trnka       Four-point scattering from Amplituhedron   
    Tseytlin    Strings in AdS and their deformations
    Vafa        On 6d SCFT's
    Vasiliev    Higher-rank fields and currents
    Warner      Resolving Black Holes via Microstate Geometries
    Witten      Opening Remarks
    Weigand     Mordell-Weil torsion and matter spectra in F-theory
    Zaldarriaga The dawn of B-mode cosmology  
    The five "vision/outlook" talks come at the end. Green Gross Maldacena Moore Strominger. Here's the entire schedule if anyone is interested:
    http://physics.princeton.edu/strings2014/Scientific_Program.shtml
    All the talks have 30 minute slots, except that the opening remarks get 15 minutes and three review talks get an hour each (Polchinski, Erdenmenger, Tachikawa on BH info, nonstring AdS/CFT apps, Susy status)
    Plenary talks will be broadcast at http://www.princeton.edu/WebMedia/

    Note: to distinguish between the two speakers named Lee, here is Sungjay Lee's profile:
    http://inspirehep.net/author/profile/Sungjay.Lee.1
    and for Sangmin Lee:
    http://inspirehep.net/author/profile/S.Lee.61
     
    Last edited: Jun 14, 2014
  13. Jun 24, 2014 #63

    marcus

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    In case anyone is interested, the slides and videos of the Strings 2014 talks are being posted here:
    http://physics.princeton.edu/strings2014/Talk_titles.shtml

    So far no videos (it is just the second day of the conference), but slides for several of the talks are now up. Here's a sample:

    Polchinski: "Black Hole Information: Spacetime versus Quantum Mechanics"
    http://physics.princeton.edu/strings2014/slides/Polchinski.pdf (this works)

    Steinhardt: "What has been learned from BICEP2?"
    apparently download from menu http://physics.princeton.edu/strings2014/Talk_titles.shtml
    My computer cannot open the file which is labeled "Steinhardt.pptx" and has size 28 MB.
    It seems to be asking for "Office" or "OpenOffice". You may be better prepared than I, to view the slides.
     
    Last edited: Jun 24, 2014
  14. Jun 28, 2014 #64

    marcus

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    Andy Strominger gave one of the 4 "vision" talks at the end of Strings 2014. His slides are online:
    http://physics.princeton.edu/strings2014/slides/Strominger.pdf
    He lists here 74 research questions (some with hints) that he collected from colleagues who proposed them as ones which might be answered in the next 5-10 years. Plus he put in his own favorite such question: explain why S = A/(4[STRIKE]h[/STRIKE]G)
    So a list of 75 including some inspiring/challenging ones. Not all are specific to Superstring/M theory and so some could be of general interest. E.g. see question #30 from Nathan Seiberg, or for that matter Strominger's own "question zero".
    Peter Woit reports planned locations of future conferences: Strings 2015 will be in Bangalore, Strings 2016 in Tsinghua, Strings 2017 in Israel, Strings 2018 in Japan and Strings 2019 in Belgium.
     
    Last edited: Jun 28, 2014
  15. Jul 27, 2014 #65

    marcus

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    Videos for some talks are now online.
    Here's link to an excellent talk by Paul Steinhardt:
    http://physics.princeton.edu/strings2014/videos/talk1h.mp4 [Broken]
     
    Last edited by a moderator: May 6, 2017
  16. Aug 16, 2014 #66
    I want to report this:

    Sapienza University of Rome 8 -12 september 2014
    Conceptual and Technical Challenges for Quantum Gravity 2014

    This conference will provide an opportunity for an encounter between different approaches and different perspectives on the quantum-gravity problem. Its main goal is to contribute to a higher level of shared knowledge among the quantum-gravity communities pursuing each specific research program.
    We plan to have plenary talks on many different approaches, including in particular string theory, loop quantum gravity, spacetime noncommutativity, causal dynamical triangulations, asymptotic safety and causal sets. We shall also welcome contributions from the perspective of philosophy of science.

    http://ctcqg2014.relativerest.org/
     
  17. Aug 20, 2014 #67

    marcus

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    Thanks! I saw this earlier but neglected to post it. It comes right on the heels of the Experimental Search for Quantum Gravity conference at ISAS Trieste. Here is the list of plenary speakers so far.
    Eric A. Bergshoeff, University of Groningen (NL)
    Massimo Bianchi, Università di Roma “Tor Vergata” (IT)
    Jeremy Butterfield, Trinity College, University of Cambridge (UK)
    Fay Dowker, Imperial College (London, UK)
    Laurent Freidel, Perimeter Institute for Theoretical Physics (Waterloo, CA)
    Jerzy Kowalski-Glikman, University of Wrocław (PL)
    Helge Kragh, Aarhus University (DK)
    Stefano Liberati, SISSA (Trieste, IT)
    Daniel Litim, University of Sussex (Brighton, UK)
    Renate Loll, Radboud University (Nijmegen, NL)
    João Magueijo, Imperial College (London, UK)
    Shahn Majid, Queen Mary, University of London (UK)
    Daniele Oriti, Max Planck Institute for Gravitational Physics (Postdam-Golm, DE)
    Carlo Rovelli, Centre de Physique Théorique de Luminy (Marseille, FR)

    It's an interesting lineup: speakers from lines of research like AsymSafeQG, CDT, NCG, Group Field Theory, QG Phenomenology, Causal Sets, Covariant LQG,...
     
  18. Aug 20, 2014 #68

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    The ILQGS Fall schedule is posted!
    Code (Text):

    Sep 2    [B]Casimir effect on a quantum geometry[/B]     Javier Olmedo   LSU
    Sep 16   [B]Cov LQG: classical action, phase space & gauge symmetries[/B]  Wolfgang Wieland PSU
    Sep 30   TBA     Brajesh Gupt    PSU
    Oct 14   [B]White holes[/B]  Carlo Rovelli   CNRS Marseille
    Oct 28   [B]New applications for LQG[/B]     Jerzy Lewandowski   University of Warszaw
    Nov 11   [B]Lorentz transformations from abstract quantum theory[/B]     Philip Hoehn  PI
    Nov 25   TBA     Derek Wise  FAU Erlangen
    Dec 9    [B]Invariance of Connections and Measures in LQC[/B]  Maximilian Hanusch Uni Paderborn
     
  19. Aug 20, 2014 #69

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    The schedule of ESQG talks has been posted.
    http://www.sissa.it/app/esqg2014/schedule.php
    Some titles and abstracts are still TBA, here are those that have been posted so far:
    Astrid Eichhorn (Perimeter Institute, Waterloo)
    Testing asymptotically safe quantum gravity through coupling to dynamical matter
    I will discuss the main idea of asymptotically safe quantum gravity. I will then focus on the effect of dynamical matter degrees of freedom, and discuss the evidence for the consistency of the asymptotic safety scenario for gravity with the Standard Model. Further, I will explain why only some models of "New Physics" seem to be compatible with asymptotic safety, thus providing a possibility to experimentally rule out asymptotic safety at the LHC or future colliders.

    Igor Pikovski (Vienna Center for Quantum Science and Technology)
    Exploring gravitational phenomena in low-energy quantum theory
    We discuss how the ability to manipulate and to control quantum systems to very high precision opens the route for new experiments on the interplay between quantum theory and general relativity. It is shown how quantum optical systems can be used for testing low energy quantum mechanics on a fixed background space-time and quantum gravity phenomenology. We consider gravitational time dilation in low-energy quantum theory and derive the resulting decoherence of composite quantum systems [1]. We also show how pulsed opto-mechanical systems can provide a means to probe possible quantum gravitational modifications of the center-of-mass canonical commutator [2]. The results demonstrate that the interplay between quantum theory and general relativity can affect even low-energy quantum systems and that it offers novel phenomena which can be probed in experiments. [1] I. Pikovski, M. Zych, F. Costa, and C. Brukner, Universal decoherence due to gravitational time dilation, arXiv:1311.1095 (2013). [2] I. Pikovski, M. R. Vanner, M. Aspelmeyer, M. Kim, and C. Brukner, Probing Planck-scale physics with quantum optics, Nature Physics 8, 393 (2012).

    Jose Manuel Carmona (Universidad de Zaragoza)
    Thresholds in the presence of Lorentz violating kinematics including modified conservation laws
    We discuss the leading Lorentz violations in the kinematics of particle processes with modified dispersion relations and modified composition law of momenta and some phenomenological implications on thresholds in different reactions.

    Giampiero Esposito (INFN, Sezione di Napoli)
    Three-body problem in effective field theories of gravity
    The quantum corrections to the Newtonian potential obtained in effective field theories of gravity are shown to produce tiny but nonnegligible effects. For example, in the restricted problem of 3 bodies, the coordinates of Lagrangian points are slightly modified, and the planetoid is no longer at equal distance from the two bodies of large mass in the configuration of stable equilibrium. The equations of the full 3-body problem are also under investigation in the presence of quantum corrections.

    Brian Keating (University of California, San Diego )
    The Discovery of B-mode Polarization by the BICEP2 Experiment
    BICEP2 is a Cosmic Microwave Background (CMB) polarimeter designed to search for the signal of gravitational waves from inflation in B-mode polarization at large angular scales. BICEP2 observed from the South Pole for three seasons from 2010-2012 and recently published results showing an excess of B-modes in the range 30 < ell < 150 with >5 sigma significance. We find that this excess can not be explained by instrumental systematics or foreground models; it is confirmed in cross-correlation with BICEP1 (at 100 and 150 GHz) and preliminary data from the Keck Array. The observed B-mode power spectrum is well fit by a lensed-LCDM cosmological model with the addition of primordial tensor fluctuations with tensor-to-scalar ratio r=0.20^{+0.07}_{-0.05}. I will discuss the BICEP2 experiment, observations, and data analysis, as well as current and planned efforts to follow up this detection

    Giulio Fabbian (SISSA)
    POLARBEAR experiment: results from the first observational campaign and the prospects
    I will present the POLARBEAR experiment, an ongoing ground-based CMB polarization experiment located in northern Chile. I will review its latest results obtained from the analysis of the data collected during the first observational campaign and discuss their implication for cosmology and fundamental physics.

    Stephon Alexander (Dartmouth)
    Parity Violating Gravitational Waves and the Standard Model
    I show how parity violating gravitational waves can simultaneously generate the observed baryon asymmetry and provide a natural period of parametric resonance of preheating at the end of inflation . I discuss how this signal of parity violation may also be observable in other sectors in theories beyond the standard model.

    Julien Grain (Institut d'Astrophysique Spatiale)
    A brief overview of loop quantum cosmology and its potential observational signatures
    Loop quantum cosmology (a symmetry-reduced quantum model of the Universe inspired by loop quantum gravity) extends the inflationary paradigm to the Planck era: the big bang singularity is replaced by a quantum bounce naturally followed by inflation. Testing for these models requires to compute the amount of cosmological perturbations produced in this quantum background and subsequently derives their footprints on the cosmic microwave background. I propose to review two theoretical approaches treating for cosmological perturbations in a quantum background (see Barrau et al. 2014 and Agullo et al. 2013), making their respective assumptions and methodology as explicit as possible. I will then show the observational consequences of those treatments focusing on the specific case of the cosmic microwave background anisotropies as a probe of the primordial Universe.

    Agnes Ferte (Institut d'Astrophysique Spatiale)
    Constraints on chiral gravity through the CMB polarization
    If parity invariance is broken in the primordial universe, the cosmic microwave background TB and EB cross-correlations, usually vanishing, become non zero. Their detection would then constrain the level of parity violation. I propose to present forecasts on the detection of this parameter by realistically estimating the uncertainties on the TB and EB spectra via the pure pseudo spectrum method, which efficiency has been shown. I will present the results of this forecast in the case of two typical experimental setups: a small-scale experiment and a large scale survey. Our results show that no constraints can be put on the level of parity violation in the former case. However a range of model would be accessible with a future CMB satellite-like mission: for instance, a parity violation of at least 50% with r = 0.2 could be detected.

    Mercedes Martin-Benito (Radboud University Nijmegen)
    Echoes of the early Universe
    By applying quantum informational and optical tools to quantum gravity theories in the very early universe, we show that the fluctuations of quantum fields as seen by late comoving observers are significantly influenced by the history of the early universe, transmitting information about the nature of the universe in timescales when quantum gravitational effects where non-negligible. This might be observable even nowadays thus used to build falsifiability tests of quantum gravity theories.

    Jonathan Granot (Open University of Israel)
    Experimental Bounds on Quantum Gravity from Fermi Observations of GRBs
    I will discuss recent searches for quantum gravity signatures using high-energy photons from gamma-ray bursts (GRBs), focusing on the search for Lorentz Invariance Violation (LIV) in the form of a dependence of the photon propagation speed on its energy. Fermi gamma-ray space telescope observations of ~8 keV to ~30 GeV photons from the short (< 1 s) GRB 090510 at a cosmological distance (z = 0.903), enabled for the first time to put a direct time of flight limit on a possible linear variation of the speed of light with photon energy that is beyond the Planck scale. Parameterizing |v/c-1| = E/E_{QG}, for deterministic LIV our most conservative limits are E_{QG}/E_{Planck} > 1.2, while less conservative limits are up to 1-2 orders of magnitude stricter. Using the same data, we have now also set Planck-scale limits on stochastic (or fuzzy) LIV - the first of this kind. I will finish by briefly outlining the prospects for future GRB observations by the Cherenkov Telescope Array (CTA) - the next generation ground based very high energy (from ~20-30 GeV to ~300 TeV) observatory.

    Carlo Rovelli (Aix-Marseille University)
    Planck Stars
    I describe a new suggestion for measurable quantum gravity effects: the bounce of a primordial Planck star.

    Anupam Mazumdar (Lancaster University)
    Resolution of Cosmological and Blackhole Singularities
    I will discuss how non-local action of higher derivative extension of Einstein's gravity could yield ghost free and devoid of any space or time like singularities.

    Francesco Cianfrani (University of Wroclaw)
    Quantum Reduced Loop Gravity: status and perspectives.
    I will present the status and the perspectives of Quantum Reduced Loop Gravity. Instead of discussing in details all the technical issues, I will focus on the relevance of this approach for grounding Loop Quantum Cosmology and for inferring a proper phenomenology for the early Universe.

    Tomasz Trzesniewski (University of Wroclaw)
    Dimensional Flow in kappa-Minkowski Spacetime
    Running of the spacetime dimension in small scales is predicted by many different approaches to Quantum Gravity, usually using a notion of the spectral dimension. This is also the case for the kappa-Minkowski spacetime, which appears in the Deformed Special Relativity and Relative Locality. The spectral dimension can easily be calculated in the (Euclidean) momentum space representation. Meanwhile, kappa-Minkowski momenta belong to the group AN(n), which can be represented as half of the de Sitter space. A novel prescription shows it can also be mapped to (half of) the Euclidean anti-de Sitter space, which gives the Euclidean version of momentum space. This allows us to calculate the kappa-Minkowski spectral dimension for different possible Laplacians, extending the known results and providing us with a possible hint for the choice of a physical Laplacian.

    Goffredo Chirco (CPT, Universite' Aix-Marseille)
    Thermally correlated states of Loop Quantum Gravity
    We define a class of states of LQG characterized by thermal correlations at the ultralocal level, which may reproduce the structure of correlations known for the perturbative quantum gravity states, in the appropriate limit. We show that these states have a consistent semiclassical interpretation, being peacked on classical values of the intrinsic geometry; and we study how these correlations propagate non-locally on the spin network. We propose these states as the fundamental quantum bricks defining the architecture of spacetime at the non perturbative level and we elaborate on the possible relevance of this proposal in the definition of a continuum limit for LQG.

    Jonathan Miller (Universidad Tecnica Federico Santa Maria)
    The effect of Quantum Gravity on astrophysical neutrino flavor observables.
    At the quantum level, an interaction of a neutrino with a graviton may trigger the collapse of the neutrino flavor eigenstate to a neutrino mass eigenstate. I will present that such an essentially quantum gravity effect may have strong consequences for neutrino oscillation phenomena in astrophysics due to the relatively large scattering cross section of relativistic neutrinos off massive sources of gravitational fields (the case of gravitational Bethe-Heitler scattering). This results in a new technique for the indirect detection of gravitons by measuring the flavor composition of astrophysical neutrinos.

    Jerzy Kowalski-Glikman (University of Wroclaw)
    Relative locality in 2+1 dimensions
    The relative locality framework is based on two general premises: nontrivial geometry of momentum space and deformed momentum conservation rule. In my talk I will show how these premises take a concrete shape in the case of particles coupled to 2+1 gravity. Then I will briefly discuss the relevance of this construction to the case of physical 3+1 dimensions.

    Giulia Gubitosi (Sapienza, University of Rome)
    Dimensional Reduction in the Early Universe

    Giacomo Rosati (ITP, University of Wroclaw)
    Deformed Lorentz Symmetry and relative locality in FRW spacetime
    An opportunity to test Planck-scale modifications of Lorentz symmetry is represented by propagation of particles from cosmological distances (as from GRBs). DSR has been investigated so far only for flat (Minkowskian) spacetimes, providing no room for interplay with cosmological redshift. Only recently a generalization to deSitter spacetime has been proposed (Phys.Rev.D86(2012)124035), relying on the recent understanding of relativity of locality in DSR. I here propose a formulation of DSR in FRW spacetimes, discussing some of the differences with the most studied scenario for broken Lorentz symmetries.

    Niccolo' Loret (Perimeter Institute, Waterloo)
    Finsler geometry and deSitter momentum space
    Finsler geometry provides a well studied generalization of Riemannian geometry which allows to account for possibly non-trivial structure of the space of con?gurations of a massive relativistic particle. Another recently developed framework for the description of modi?ed relativistic particle kinematics relies on the description of the particle momentum-space as a curved (pseudo-Riemannian) manifold. We will show that in some cases these two frameworks give equivalent descriptions of the physical properties of a relativistic particle, when its momentum-space is characterized by a deSitter metric and the spacetime is ?at. The generalization of this result could provide a useful mathematical tool to formalize Deformed Special Relativity phenomenology to curved spacetimes.

    Gianluca Castignani (SISSA)
    Gamma-ray bursts as laboratories for quantum effects of gravity
    Gamma-ray bursts (GRBs) are the most powerful explosions in the Universe. Most GRBs detected by the Fermi Gamma-ray Space Telescope exhibit a possible delay of up to about 10 seconds between the trigger time of the hard X-ray signal as measured by the Fermi Gamma-ray Burst Monitor (GBM) and the onset of the MeV-GeV counterpart detected by the Fermi Large Area Telescope (LAT). This delay may hint at important physics, whether it is due to the intrinsic variability of the inner engine or related to quantum dispersion effects (e.g. modified dispersion relations) in the velocity of light propagation from the sources to the observer. We searched for the presence of time lags between the LAT and GBM light curves for the five brightest GRBs of the 1st Fermi-LAT Catalog by means of cross correlation analysis. Time lags that are significantly different from zero and consistent with those reported in the literature are found for all the GRBs in our sample by mean of cross correlation analysis. Our analysis reveals the complexity of the time behavior of the GBM and LAT light curves and suggests that the delays should be ascribed to intrinsic physical mechanisms. Better sensitivity and a larger sample might put constraints on a possible origin of the delays in the context of modified dispersion relations and will allow to assess whether time lags are universally present in the early GRB emission.

    John Kelley (Univ. of Wisconsin, Madison)
    Observation of High-energy Astrophysical Neutrinos with the IceCube Detector
    The IceCube Neutrino Observatory is a cubic-kilometer-scale neutrino detector built into the ice sheet at the geographic South Pole. IceCube has recently observed a diffuse flux of high-energy astrophysical neutrinos with deposited energies up to 2 PeV. The detection of neutrinos at such energies, as well as features of their energy spectrum and flavor ratios, can be used to constrain potential phenomenological effects of quantum gravity. I will discuss the latest measurements from IceCube of these high-energy neutrinos and the implications for such constraints.

    David Mattingly (University of New Hampshire)
    Lorentz violating effective field theories

    Sabine Hossenfelder (Nordita)
    Space-time Defects
    One of the most important questions in quantum gravity is whether or not space-time is fundamentally discrete or continuous. However, directly finding evidence for space-time discreteness has turned out to be difficult if not impossible. In my talk I will discuss the possibility to look for defects in the discrete structure rather than the discrete structure itself. Interestingly, these space-time defects can be modeled without violating Lorentz-invariance, and they can become observable by affecting the propagation of particles.

    Daniele Oriti (Albert Einstein Institute)
    The universe as a quantum gravity condensate
    We discuss the geometrogenesis scenario in quantum gravity and the role it may play in the context of loop quantum gravity and group field theory. We also emphasise the connection with other ideas of emergent space-time and with analogue gravity models. We report on recent results, in the group field theory formalism, aiming at realising this scenario and in particular at the derivation of effective cosmological dynamics from group field theory condensates. In light of these results, we suggest several directions to explore to extract testable consequences of this picture of the early universe.
     
  20. Sep 3, 2014 #70

    marcus

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    Slides for some of the ESQG talks have been put online
    http://www.sissa.it/app/esqg2014/
    Here is the speaker list with asterisks marking those who have already given their talks and whose slides have already been posted:
    http://www.sissa.it/app/esqg2014/speakers.php


    Code (Text):
    Stephon Alexander   Dartmouth
    Dionigi Benincasa   SISSA
    Pawel Bielewicz         SISSA
    Jose Manuel Carmona*    Universidad de Zaragoza
    Gianluca Castignani SISSA
    Goffredo Chirco         CPT, Universite' Aix-Marseille
    Francesco Cianfrani University of Wroclaw
    Paolo Creminelli*   ICTP, Trieste
    Astrid Eichhorn*    Perimeter Institute, Waterloo
    Giampiero Esposito* INFN, Sezione di Napoli
    Giulio Fabbian          SISSA
    Agnes Ferte*            Institut d'Astrophysique Spatiale
    Julien Grain*           Institut d'Astrophysique Spatiale
    Jonathan Granot         Open University of Israel
    Giulia Gubitosi         Sapienza, University of Rome
    Sabine Hossenfelder Nordita
    Brian Keating*          University of California, San Diego
    John Kelley         Univ. of Wisconsin, Madison
    Jerzy Kowalski-Glikman  University of Wroclaw
    Niccolo' Loret          Perimeter Institute, Waterloo
    Joao Magueijo           Imperial College, London
    Francesco Marin*    Universita' di Firenze and INFN
    Mercedes Martin-Benito* Radboud University Nijmegen
    David Mattingly         University of New Hampshire
    Anupam Mazumdar         Lancaster University
    Jakub Mielczarek    Jagiellonian University, Crakow
    Jonathan Miller         Universidad Tecnica Federico Santa Maria
    Daniele Oriti           Albert Einstein Institute
    Igor Pikovski           Vienna Center for Quantum Science and Technology
    Giacomo Rosati          ITP, University of Wroclaw
    Carlo Rovelli           Aix-Marseille University
    Floyd Stecker           NASA - Goddard Space Flight Center
    Tomasz Trzesniewski University of Wroclaw
    Francesca Vidotto   Radboud University Nijmegen
     
    Last edited: Sep 3, 2014
  21. Sep 3, 2014 #71

    marcus

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    I've gathered the titles and abstracts of ESQG talks for which the slides have already been posted. Hopefully more links will show up tomorrow, as the workshop proceeds.
    Links to the slides PDF are included alongside the speaker's name in the schedule, here:
    http://www.sissa.it/app/esqg2014/schedule.php



    Jose Manuel Carmona (Universidad de Zaragoza) (slides)
    16:30, Mon 1st Sep 2014
    Thresholds in the presence of Lorentz violating kinematics including modified conservation laws
    We discuss the leading Lorentz violations in the kinematics of particle processes with modified dispersion relations and modified composition law of momenta and some phenomenological implications on thresholds in different reactions.

    Paolo Creminelli (ICTP, Trieste) (slides)
    11:15, Tue 2nd Sep 2014
    B-mode cosmology
    The experimental sensitivity to B-modes is now in an interesting regime for primordial tensor modes. I will review the robustness of the tensor mode prediction in inflation and speculate about what we can learn if tensor modes are detected.

    Astrid Eichhorn (Perimeter Institute, Waterloo) (slides)
    10:45, Mon 1st Sep 2014
    Testing asymptotically safe quantum gravity through coupling to dynamical matter
    I will discuss the main idea of asymptotically safe quantum gravity. I will then focus on the effect of dynamical matter degrees of freedom, and discuss the evidence for the consistency of the asymptotic safety scenario for gravity with the Standard Model. Further, I will explain why only some models of "New Physics" seem to be compatible with asymptotic safety, thus providing a possibility to experimentally rule out asymptotic safety at the LHC or future colliders.

    Giampiero Esposito (INFN, Sezione di Napoli) (slides)
    17:00, Mon 1st Sep 2014
    Three-body problem in effective field theories of gravity
    The quantum corrections to the Newtonian potential obtained in effective field theories of gravity are shown to produce tiny but nonnegligible effects. For example, in the restricted problem of 3 bodies, the coordinates of Lagrangian points are slightly modified, and the planetoid is no longer at equal distance from the two bodies of large mass in the configuration of stable equilibrium. The equations of the full 3-body problem are also under investigation in the presence of quantum corrections.

    Agnes Ferte (Institut d'Astrophysique Spatiale) (slides)
    17:00, Tue 2nd Sep 2014
    Constraints on chiral gravity through the CMB polarization
    If parity invariance is broken in the primordial universe, the cosmic microwave background TB and EB cross-correlations, usually vanishing, become non zero. Their detection would then constrain the level of parity violation. I propose to present forecasts on the detection of this parameter by realistically estimating the uncertainties on the TB and EB spectra via the pure pseudo spectrum method, which efficiency has been shown. I will present the results of this forecast in the case of two typical experimental setups: a small-scale experiment and a large scale survey. Our results show that no constraints can be put on the level of parity violation in the former case. However a range of model would be accessible with a future CMB satellite-like mission: for instance, a parity violation of at least 50% with r = 0.2 could be detected.

    Julien Grain (Institut d'Astrophysique Spatiale) (slides)
    16:30, Tue 2nd Sep 2014
    A brief overview of loop quantum cosmology and its potential observational signatures
    Loop quantum cosmology (a symmetry-reduced quantum model of the Universe inspired by loop quantum gravity) extends the inflationary paradigm to the Planck era: the big bang singularity is replaced by a quantum bounce naturally followed by inflation. Testing for these models requires to compute the amount of cosmological perturbations produced in this quantum background and subsequently derives their footprints on the cosmic microwave background. I propose to review two theoretical approaches treating for cosmological perturbations in a quantum background (see Barrau et al. 2014 and Agullo et al. 2013), making their respective assumptions and methodology as explicit as possible. I will then show the observational consequences of those treatments focusing on the specific case of the cosmic microwave background anisotropies as a probe of the primordial Universe.

    Brian Keating (University of California, San Diego ) (slides)
    9:00, Tue 2nd Sep 2014
    The discovery of primordial B-mode polarization
    The era of Cosmic Microwave Background B-mode polarization cosmology has recently begun. The BICEP2 telescope observed from the South Pole for three seasons (2010�2012) and released results showing an excess of B-modes in the range 30 < ell < 150 with >5 sigma significance. We find that this excess can not be explained by instrumental systematics or foregrounds. The signal was confirmed in cross-correlation with BICEP1 (at 100 and 150 GHz) and preliminary data from the Keck Array. The observed B-mode power spectrum is well-fit by a lensed-LCDM cosmological model with the addition of primordial tensor fluctuations with tensor-to-scalar ratio r=0.20^{+0.07}_{-0.05}. I will discuss the BICEP2 experiment, observations, and data analysis, as well as current and planned efforts to follow up this detection.

    Francesco Marin (Universita' di Firenze and INFN) (slides)
    14:30, Mon 1st Sep 2014
    Tests of quantum gravity with macroscopic mechanical oscillators
    General relativity and quantum physics are expected to merge at the Planck scale, defined by distances of the order of 1.6x10^-35 m and/or extremely high energies of the order of 1.2x10^19 GeV. Since the study of particles collisions around the Planck energy is well beyond the possibilities of current and foreseeable accelerators, high-energy astronomical events (e.g. gamma-ray bursts) have been considered as the privileged natural system to unveil quantum gravitational effects. This common view has been enriched in the last years thanks to a number of studies proposing that signatures of the Planck-scale physics could manifest also at low energies. It is indeed widely accepted that, when gravity is taken into account, deviations from standard quantum mechanics are expected. In particular, we have recently shown that the very low mechanical energy achieved and measured in a vibration mode of a massive object can set an upper limit to possible modifications of the Heisenberg uncertainty principle, that are expected as an effect of gravity. We have indeed exploited the sub- millikelvin cooling of the normal modes of the ton-scale gravitational wave detector AURIGA at this purpose [1]. Here we will discuss some possible interpretations of our results, including possible consequences on deformed commutators, and an upper limit on the length scale at which quantum fluctuations of the space- time geometry should come into play[2]. We will also describe the preliminary results of a series of experiments devoted to investigate possible modifications to the dynamics of micro-oscillators, due to modified Heisenberg relations. [1] F. Marin et al., "Gravitational bar detectors set limits to Planck-scale physics on macroscopic variables", Nature Phys. 9, 71 (2013) [2] F. Marin et al., "Investigation of Planck scale physics by the AURIGA gravitational bar detector", to be published on New J. Phys.

    Mercedes Martin-Benito (Radboud University Nijmegen) (slides)
    17:30, Tue 2nd Sep 2014
    Echoes of the early Universe
    By applying quantum informational and optical tools to quantum gravity theories in the very early universe, we show that the fluctuations of quantum fields as seen by late comoving observers are significantly influenced by the history of the early universe, transmitting information about the nature of the universe in timescales when quantum gravitational effects where non-negligible. This might be observable even nowadays thus used to build falsifiability tests of quantum gravity theories.
     
  22. Sep 4, 2014 #72

    marcus

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    More slide sets from the ESQG have been posted. Of particular interest, I think, is the talk by Vidotto on the Planck Star model of BH. I'll give the link here for easy access.
    http://www.sissa.it/app/esqg2014/schedule.php
    http://www.sissa.it/app/esqg2014/slides/Vidotto_Trieste_2014.pdf

    Pawel Bielewicz (SISSA) (slides)
    10:30, Tue 2nd Sep 2014
    Planck 2013 cosmological results
    I will present the Planck experiment and review the first cosmological results released in 2013. I will also briefly discuss prospects for the planned this year next release of the cosmological data.

    Giulio Fabbian (SISSA) (slides)
    14:30, Tue 2nd Sep 2014
    POLARBEAR experiment: results from the first observational campaign and the prospects
    I will present the POLARBEAR experiment, an ongoing ground-based CMB polarization experiment located in northern Chile. I will review its latest results obtained from the analysis of the data collected during the first observational campaign and discuss their implication for cosmology and fundamental physics.

    Jerzy Kowalski-Glikman (University of Wroclaw) (slides)
    11:15, Thu 4th Sep 2014
    Relative locality in 2+1 dimensions
    The relative locality framework is based on two general premises: nontrivial geometry of momentum space and deformed momentum conservation rule. In my talk I will show how these premises take a concrete shape in the case of particles coupled to 2+1 gravity. Then I will briefly discuss the relevance of this construction to the case of physical 3+1 dimensions.

    Anupam Mazumdar (Lancaster University) (slides)
    15:15, Wed 3rd Sep 2014
    Resolution of Cosmological and Blackhole Singularities
    I will discuss how non-local action of higher derivative extension of Einstein's gravity could yield ghost free and devoid of any space or time like singularities.

    Jonathan Miller (Universidad Tecnica Federico Santa Maria) (slides)
    9:00, Thu 4th Sep 2014
    The effect of Quantum Gravity on astrophysical neutrino flavor observables.
    At the quantum level, an interaction of a neutrino with a graviton may trigger the collapse of the neutrino flavor eigenstate to a neutrino mass eigenstate. I will present that such an essentially quantum gravity effect may have strong consequences for neutrino oscillation phenomena in astrophysics due to the relatively large scattering cross section of relativistic neutrinos off massive sources of gravitational fields (the case of gravitational Bethe-Heitler scattering). This results in a new technique for the indirect detection of gravitons by measuring the flavor composition of astrophysical neutrinos.

    Tomasz Trzesniewski (University of Wroclaw) (slides)
    17:00, Wed 3rd Sep 2014
    Dimensional Flow in kappa-Minkowski Spacetime
    Running of the spacetime dimension in small scales is predicted by many different approaches to Quantum Gravity, usually using a notion of the spectral dimension. This is also the case for the kappa-Minkowski spacetime, which appears in the Deformed Special Relativity and Relative Locality. The spectral dimension can easily be calculated in the (Euclidean) momentum space representation. Meanwhile, kappa-Minkowski momenta belong to the group AN(n), which can be represented as half of the de Sitter space. A novel prescription shows it can also be mapped to (half of) the Euclidean anti-de Sitter space, which gives the Euclidean version of momentum space. This allows us to calculate the kappa-Minkowski spectral dimension for different possible Laplacians, extending the known results and providing us with a possible hint for the choice of a physical Laplacian.

    Francesca Vidotto (Radboud University Nijmegen) (slides)
    14:30, Wed 3rd Sep 2014
    What can we learn from Loop Quantum Cosmology? The case of Planck Stars
    Loop Quantum Cosmology suggests that cosmological singularities are generically resolved by quantum effects. This can be understood at the effective level as the appearance of a repulsive force in the deep quantum-gravity regime. A similar mechanism should take place in the interior of black holes, whose singularity would then be replaced by a core of Planckian energy density. Such Planck Star provides a remnant which can help avoid the information paradox. Furthermore, if the evaporation ends with an explosive event, the Planck star could provide a precise astrophysical signal. Using the current models for primordial black holes and the bounds given by dark-matter abundance, this signal could be compatible with a specific kind of gamma rays, that we have already observed.
    http://www.sissa.it/app/esqg2014/slides/Vidotto_Trieste_2014.pdf
     
    Last edited: Sep 4, 2014
  23. Sep 15, 2014 #73

    marcus

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    http://relativity.phys.lsu.edu/ilqgs/schedulefa14.html
    Wieland's talk is a couple of days from now, on Tuesday 16th.
    The ILQGS schedule has been updated:
    http://relativity.phys.lsu.edu/ilqgs/
    Code (Text):

    Sep 2    Casimir effect on a quantum geometry     Javier Olmedo        LSU
    Sep 16   Cov LQG: classical action, phase space & gauge symmetries  Wolfgang Wieland PSU
    Sep 30   Phenomenological consequences of quantum geometries in LQC Brajesh Gupt  PSU
    Oct 14   White holes     Carlo Rovelli     CNRS Marseille
    Oct 28   New applications for LQG     Jerzy Lewandowski     University of Warszaw
    Nov 11   Lorentz transformations from abstract quantum theory     Philip Hoehn  PI
    Nov 25   SL(2,C)Chern-Simons&Spinfoam Gravity w Cosm.Const Hal Haggard, Aldo Riello Bard/PI
    Dec 9    Invariance of Connections and Measures in LQC  Maximilian Hanusch Uni Paderborn
    (
     
    Last edited: Nov 13, 2014
  24. Dec 28, 2014 #74

    marcus

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    http://www.gravity.physik.fau.de/events/tux3/tux3.shtml

    Third EFI Winter Conference on QG
    Monday February 16 to Friday February 20 2015 Tux, Austria
    General Information

    The conference aims to bring together experts on canonical and covariant loop quantum gravity and related topics, in the scenic village of Tux, in the Austrian alps.

    tux_glacier.jpg
    Hintertux Glacier
    Topics covered by the conference include
    • canonical and covariant LQG
    • QFT in curved spacetime
    • quantum physics of⁄near black holes
    • physical observables of general relativity
    Organizers of the conference are
    • Norbert Bodendorfer <Norbert.Bodendorfer_at_googlemail.com>
    • Jerzy Lewandowski <Jerzy.Lewandowski_at_fuw.edu.pl>
    • Hanno Sahlmann <hanno.sahlmann_at_gravity.fau.de>
    Universytet Warszawski
    Friedrich-Alexander Universität Erlangen-Nürnberg

    The schedule will keep the mornings free for work, skiing or hiking. Talks will start around 13:00 and may run till 19:00 or 20:00.
    Participants
    ... Here is a partial list that will be updated from time to time:
    • Ivan Agullo, Louisiana State University
    • Martin Ammon University of Jena
    • Mehdi Assanioussi, Warsaw University
    • Norbert Bodendorfer, Warsaw University
    • Goffredo Chirco University Aix-Marseille
    • Andrea Dapor, Warsaw University
    • Andrzej Dragan, Warsaw University
    • Maciej Dunajski, Cambridge University
    • Maite Dupuis, University of Waterloo
    • Beatriz Elizaga Complutense University of Madrid
    • Christian Fleischhack, University Paderborn
    • Marc Geiller, Pennsylvania State University
    • Florian Girelli, University of Waterloo
    • Muxin Han, University Erlangen-Nürnberg
    • Maximilian Hanusch, University Paderborn
    • Jeff Hnybida Perimeter Institute
    • Stefan Hollands*, Leipzig University
    • Marcin Kisielowski, University Erlangen-Nürnberg
    • Kamil Lacina*, Jagiellonian University Krakow
    • Miklos Långvik, Helsinki University
    • Jerzy Lewandowski, Warsaw University
    • Ilkka Maekinen, Warsaw University
    • Mercedes Martin-Benito Radboud University Nijmegen
    • Guillermo Mena Marugan, Instituto de Estructura de la Materia - CSIC
    • Tomasz Pawlowski, Andres Bello University
    • Jorge Pulin, Louisiana State University
    • Saeed Rastgoo, Autonomous University Mexico City
    • Carlo Rovelli*, University Aix-Marseille
    • Hanno Sahlmann, University Erlangen-Nürnberg
    • John Schliemann, University Regensburg
    • Atousa Shirazi* Florida Atlantic University
    • Jan Sikorski, Warsaw University
    • Simone Speziale, University Aix-Marseille
    • Jedrzej Swiezewski, Warsaw University
    • Francesca Vidotto, Radboud University Nijmegen
    • Wolfgang Wieland, Pennsylvania State University
    • Edward Wilson-Ewing Albert-Einstein-Institute
    • Antonia Zipfel, Warsaw University


    *: To be confirmed.
     
  25. Dec 28, 2014 #75

    marcus

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    Science Advisor
    Gold Member
    Dearly Missed

    Loops '15 (Erlangen July 6-10):
    http://www.gravity.physik.fau.de/events/loops15/loops15.shtml

    MarcelGrossmann meeting (Rome July 12-18):
    http://www.icra.it/mg/mg14/
    The triennial MG meetings cover a wide range of topics (astrophysics, observational cosmology, classical gravity etc etc.) Abhay Ashtekar is one of the invited speakers. Some 70 parallel sessions are planned, of which 4 will be devoted to string topics and 3 to QG. Here are the topics and chairpersons of the latter:
    Quantum Gravity
    QG1
    Loop Quantum Gravity, Quantum Geometry, Spin Foams (Jerzy Lewandowski)
    QG2 Quantum Gravity Phenomenology (Giovanni Amelino-Camelia)
    QG3 Loop quantum gravity: cosmology and black holes (Jorge Pullin, Parampreet Singh)
    As a sample, here is Jerzy Lewandowski's brief statement about what's to be covered in session QG1:
    ==quote==
    Jerzy LEWANDOWSKI
    Parallel Session: QG1 - Loop Quantum Gravity, Quantum Geometry, Spin Foams
    Description: Loop Quantum Gravity (LQG), a framework suited to quantize general relativity, has seen rapid progress in the last three years. The results achieved strongly suggest that the goal of finding a working and predictive quantum theory of gravity is within reach. For specific kinds of matter couplings, a way to drastically simplify the dynamics and its physical interpretation has been discovered. It gives rise to a set of examples of theories of gravity coupled to the fields in which the canonical quantization scheme can be completed. Independently, there have been important breakthroughs in the path integral formulation of the theory related to the so called Spin Foam Models. The session will review the results of canonical Loop Quantum Gravity and Spin Foam Models with the emphasis on the models admitting local degrees of freedom without the symmetry (or any other) reduction. Related approaches to quantum gravity will be also welcome. The common theme is the background independent quantization of Einstein's gravity and the occurrence of quantum geometry.
    ==endquote==
     
    Last edited: Dec 28, 2014
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