Register to reply

Introduction To Loop Quantum Gravity

by marlon
Tags: loop quantum gravity
Share this thread:
marcus
#199
Oct18-09, 08:08 PM
Astronomy
Sci Advisor
PF Gold
marcus's Avatar
P: 23,084
MTd2 found how to get the videos of the talks at Loops 2009, the big Loops conference at Beijing this summer.
You go to this catalog
http://www.mighty-security.com/loop/resource.htm
and you copy down the item number of the talk you want
and go to another site and request that number.

For example to get Ashtekar's talk, get the plenary session video for August 4 (8-4)
For Rovelli's, the plenary session for August 5.

Looking at the catalog, this means for Ashtekar it is serial number
8953789510079792

For Rovelli it would be
8605657721191707

For, say, Dan Oriti talking about Group Field Theory, it would be the August 7 plenary session
5570901362601769
==========================
Now suppose the video file can't be handled or there is some computer problem, they also have audio-only
And in that case the serial numbers for the same three plenary sessions are
8350111663470163
1930906596035020
1769207291471637

Let's hope some of these work. I'm going to give them a try.

It says: "go to http://file.mofile.com and enter the “pickup code” in the box at the top of the page."

So I'm going to mofile.com and entering the number 8605657721191707 which is the one for the Wednesday August 5 morning plenary session.

For more listings of the program timetable:
http://www.mighty-security.com/loop/timetable1.htm
http://www.mighty-security.com/loop/timetable2.htm
http://www.mighty-security.com/loop/timetable3.htm
http://www.mighty-security.com/loop/timetable4.htm
and so forth.

Well it didn't work for me! I went to mofile.com and put in the correct number 8605657721191707 in the right box
and things started to happen, but the screens were in Chinese! It wanted me to click on a button to continue but I couldn't read what I was agreeing to if I clicked. So being a cautious person, I bailed out.

Maybe it was working OK and I just should have clicked and continued. But it just wasn't "wai-gwo-ren" friendly, so I bailed. I think wai-gwo means foreign and ren means person.

Maybe someone who reads Chinese will try the mofile.com site out and give us a little coaching on how to proceed.
marcus
#200
Oct23-09, 11:47 AM
Astronomy
Sci Advisor
PF Gold
marcus's Avatar
P: 23,084
The Asymptotic Safety conference starts 5 November, less than 2 weeks away. It's an important landmark, perhaps a turning point. Interest in AsymSafe QG has revived some 30 years after Weinberg presented the idea at Erice (Sicily) in 1976.

Weinberg is working on it again and takes a sober cautious attitude. Not a sure bet, but deserves to be worked on. An alternative to string, as a way to arrive at unified fundamental description of the world. Also the running of constants like Newton G and the cosmo Lambda could provide natural mechanisms to explain cosmological phenomena such as inflation.
So AsymSafe has a key resonance with the currently hot field of cosmology---early universe in particular.

We might want to study the lineup of conference speakers and what they are talking about:
==excerpts from Perimeter host page, edited for compactness==

Thursday, November 5, 2009
8:30 - 9:20 AM Registration
9:20-9:30 AM Introductory Remarks
9:30 - 10:30 AM Steven Weinberg, University of Texas Prospects for Asymptotic Safety
11:00 AM – 12:00 PM Martin Reuter, Mainz University TBA
2:00 – 3:00 PM Jean Zinn-Justin, CEA, Saclay TBA
3:00 - 4:00 PM Holger Gies, ITP, Jena University Mechanisms of Asymptotic Safety
4:30 - 5:30 PM B.F.L. Ward, Baylor University Asymptotic Safety and Resummed Quantum Gravity

Friday, November 6, 2009
9:30-10:30 AM Lee Smolin, Perimeter Institute Asymptotic safety in the light of our modern understanding of quantum geometry
11:00AM – 12:00 PM Renate Loll, Utrecht University TBA
2:00 – 3:00 PM Max Niedermaier, Tours University Gravitational fixed points and asymptotic safety from perturbation theory
3:00-4:00 PM Frank Saueressig, Mainz University TBA
4:30-6:00 PM TBA
6:00PM Banquet Dinner

Saturday, November 7, 2009
9:30-10:30 AM Arkady Tseytlin, Imperial College, London Comments on UV divergences in quantum gravity
11:00AM – 12:00 PM Vincent Rivasseau, Universite Paris-Sud XI, Orsay TBA
2:00 – 3:00 PM Alfio Bonanno, INAF, Catania The mass-inflation phenomenon in the asymptotic safety scenario
3:00-4:00 PM John Joseph M. Carrasco, UCLA Perturbative cancellations in gravity theories
4:30-6:00PM TBA

Sunday, November 8, 2009
9:30 - 10:30 AM Jan Ambjorn, Utrecht University TBA
11:00AM – 12:00 PM Daniel Litim, University of Sussex TBA
2:00 PM "Gravity at a Lifgarbagez Point" workshop begins at 2:00pm
(Please note: Participants from the "Asymptotic Safety" workshop are welcome to stay for this afternoon's talks during the "Gravity at a Lifgarbagez Point" workshop.)

==endquote==
Another talk has been listed, but not yet assigned a time-slot:
Michael Scherer Friedrich-Schiller-Universität A mechanism for Asymptotic Safety of chiral Yukawa systems
http://www.perimeterinstitute.ca/en/...0_Years_Later/
I have edited out much of the nonessential detail such as coffeebreaks, discussion, lunch, and room locations. I expect, since it is Perimeter, video of talks will appear online.
I note that Lee Smolin authored some of the early papers on AsymSafety, back in the 1980s, while postdoc at Princeton IAS, so it's not an unfamiliar topic for him. I'm especially curious to hear what both he and Renate Loll have to say. Also Bonanno in his talk on Saturday, because he has worked a lot on the connection between AsymSafe QG and early universe cosmology--some potentially elegant connections.

The chief organizer of the conference is Roberto Percacci
http://www.perimeterinstitute.ca/ind...berto_Percacci
Often the organizer will act as host and not present a paper of his own, but will instead introduce the others. However in this case, since Percacci is one of the most active researchers and has contributed significantly to the field, one might hope that he doubles as a participant.
Percacci gave a talk at Zakopane in June 2009 which covered recent developments in AsymSafe, focusing on evidence for the UV fixed point. The PDF of his slides is here
http://th-www.if.uj.edu.pl/school/20...s/percacci.pdf
He has a FAQ and bibliography on AsymSafe here
http://www.percacci.it/roberto/physics/as/
Here is the AsymSafe FAQ:
http://www.percacci.it/roberto/physics/as/faq.html
marcus
#201
Oct25-09, 11:49 AM
Astronomy
Sci Advisor
PF Gold
marcus's Avatar
P: 23,084
Jerzy Lewandowski has essentially codified Loop Foam gravity for us.
This had to happen, and there had to be a definitive 2009 exposition of the basics.
So far the best I know of is Jerzy's
http://arxiv.org/abs/0909.0939
Spin-Foams for All Loop Quantum Gravity
and the audio+slides version is at ILQGS
http://relativity.phys.lsu.edu/ilqgs...wski102009.pdf
http://relativity.phys.lsu.edu/ilqgs...wski102009.wav
http://relativity.phys.lsu.edu/ilqgs/

Something that impressed me, that may seem irrelevant, is how strongly Jerzy stressed the seminal importance of work by Michael Reisenberger done around 1994-1998. Here is a 1990 photo of MR at the Vatican Observatory
http://www34.homepage.villanova.edu/...eopold1990.jpg
Now Reisenberger is senior faculty at the Montevideo Instituto de Fisica. He and Rodolfo Gambini are the two top QG people at University of Montevideo.

Reisberger's 1994 paper was called Worldsheet formulations of gauge theories and gravity http://arxiv.org/abs/gr-qc/9412035 It was written while he was still at Utrecht, at Gerard 't Hooft's ITP.
His 1997 paper with Carlo Rovelli was called "Sum over Surfaces'' form of Loop Quantum Gravity http://arxiv.org/abs/gr-qc/9612035 This was written while he was at the Schrödinger Institute in Vienna, and also at Montevideo.
A 1998 paper that Jerzy says should still be studied more (still has germinal undeveloped ideas) is called On relativistic spin network vertices http://arxiv.org/abs/gr-qc/9809067

Jerzy points to these as the founding papers of the spinfoam approach, the genesis of the idea. He also acknowledges learning a lot from John Baez clear 2000 exposition, and the review paper by Perez.

Jerzy presents a development of the spinfoam concept that appears in a certain sense natural. He defines the vertex formula for the foam using an enclosing spinnetwork---without invoking terms like "10j symbol" or "15j symbol". If you accept the idea of cylinder function (basic to the uniqueness theorem of "L.O.S. & T.") then the spinnetwork idea is not ad hoc---it flows naturally from the cylinderfunctions on the space of connections. And then the spinfoam idea flows naturally from the spinnetwork idea. He avoids all disconnects between the ideas.

And he seems to be saying that he was helped to re-understand the spinfoam concept by going back to Reisenberger's initial vision of it, or his preliminary glimpse. After he has finished the development, he can derive the current spinfoam vertex formulas, such as the Engle-Livine- Pereira-Rovelli, and see how the technical numbers like the angular momentum "j" symbols arise.

Lewandowski has been a major force in making Loop-and-related physics mathematically rigorous. His long collaboration with Ashtekar, spanning many years and many papers, had this main thrust.

If the organizers of the September 2009 Corfu School eventually succeed in putting online the 5-hour series of lectures by Carlo Rovelli, this would be what I'd say was the current definitive version of Loop Foam gravity. But we don't have those lectures as online media yet. At least for time being, Jerzy's paper and talk will fill the bill.

Here's a current photo of Reisenberger, one of 9 snapshots of Theiss scientists.
http://www.theissresearch.org/scientists/
It's alphabetical so scroll down.

If anyone wants to google more information about the University of Montevideo, the official name is UDELAR universita de la republica. Montevideo is capital of Uruguay, which is a Republic, so the main Uni is the University of the Republic. Here is the Montevideo Institute of Physics page:
http://www.fisica.edu.uy/
and here's the faculty list:
http://www.fisica.edu.uy/integrantes.html
atyy
#202
Oct25-09, 01:03 PM
Sci Advisor
P: 8,317
http://arxiv.org/abs/0909.0939

v1. The second paper we appreciate so much is the derivation of the new spin-foam model from the Holst action by Engle, Livine, Pereira and Rovelli [6]. Those two excellent works brought spin-foams closer to LQG. On the other hand, we regret have not considered here closer the Freidel-Krasnov model [12].

v2. The second paper we appreciate so much is the derivation of the new spin-foam model from the Holst action by Engle, Livine, Pereira and Rovelli [6]. Those two excellent works brought spin-foams closer to LQG. On the other hand, the works that should be and will be considered closer in the spirit of the current paper, are the Freidel-Krasnov model [15] (especially in the range of γ in which that model does not overlap with EPRL). Also the pioneering works of Reisenberger [2, 11, 13] contain a lot of ideas that still have not been explored enough in the literature.

v2 is much better (sociologically for me) - I am quite suspicious of Rovelli unless Freidel or Reisenberger are coauthors.
marcus
#203
Oct31-09, 02:00 PM
Astronomy
Sci Advisor
PF Gold
marcus's Avatar
P: 23,084
The Asymptotic Safety conference starts 5 November, just a few days from now. Interest in AsymSafe QG has revived some 30 years after Weinberg presented the idea at Erice (Sicily) in 1976.

A more complete list conference speakers and topics is now available:
==excerpts from Perimeter host page, edited for compactness==

Thursday, November 5, 2009
8:30 - 9:20 AM Registration
9:20-9:30 AM Introductory Remarks
9:30 - 10:30 AM Steven Weinberg, University of Texas Prospects for Asymptotic Safety
11:00 AM – 12:00 PM Martin Reuter, Mainz University Gravitational average action and asymptotic safety: past and future
2:00 – 3:00 PM Jean Zinn-Justin, CEA, Saclay Asymptotic safety: a review
3:00 - 4:00 PM Holger Gies, ITP, Jena University Mechanisms of Asymptotic Safety
4:30 - 5:30 PM B.F.L. Ward, Baylor University Asymptotic Safety and Resummed Quantum Gravity

Friday, November 6, 2009
9:30-10:30 AM Lee Smolin, Perimeter Institute Asymptotic safety in the light of our modern understanding of quantum geometry
11:00AM – 12:00 PM Renate Loll, Utrecht University TBA
2:00 – 3:00 PM Max Niedermaier, Tours University Gravitational fixed points and asymptotic safety from perturbation theory
3:00-4:00 PM Frank Saueressig, Mainz University Exploring the Theory Space of Asymptotically Safe Quantum Gravity
4:30-5:00 PM Elisa Manrique, Mainz University TBA
5:00-5:30 PM Christophe Rahmede, University of Sussex TBA

Saturday, November 7, 2009
9:30-10:30 AM Arkady Tseytlin, Imperial College, London Comments on UV divergences in quantum gravity
11:00AM – 12:00 PM Vincent Rivasseau, Universite Paris-Sud XI, Orsay TBA
2:00 – 3:00 PM Alfio Bonanno, INAF, Catania The mass-inflation phenomenon in the asymptotic safety scenario
3:00-4:00 PM John Joseph M. Carrasco, UCLA Perturbative cancellations in gravity theories
4:30-5:00PM Gian Paolo Vacca, INFN, Bologna TBA
5:00-5:30PM Michael Scherer ITP, Jena University A mechanism for Asymptotic Safety of chiral Yukawa systems

Sunday, November 8, 2009
9:30 - 10:30 AM Jan Ambjorn, Utrecht University CDT and asymptotic safety
11:00AM – 12:00 PM Daniel Litim, University of Sussex TBA

2:00 PM "Gravity at a Lifgarbagez Point" workshop begins at 2:00pm
(Please note: Participants from the "Asymptotic Safety" workshop are welcome to stay for this afternoon's talks during the "Gravity at a Lifgarbagez Point" workshop.)

==endquote==

http://www.perimeterinstitute.ca/en/...0_Years_Later/
I have edited out nonessential detail such as coffeebreaks, discussion sessions, meals, and room locations. Since it is Perimeter, video of talks might appear online.


The chief organizer of the conference is Roberto Percacci
http://www.perimeterinstitute.ca/ind...berto_Percacci
Percacci gave a talk at Zakopane in June 2009 which covered recent developments in AsymSafe, focusing on evidence for the UV fixed point. The PDF of his slides is here
http://th-www.if.uj.edu.pl/school/20...s/percacci.pdf
He has a FAQ and bibliography on AsymSafe here
http://www.percacci.it/roberto/physics/as/
Here is the AsymSafe FAQ:
http://www.percacci.it/roberto/physics/as/faq.html
marcus
#204
Nov4-09, 07:30 PM
Astronomy
Sci Advisor
PF Gold
marcus's Avatar
P: 23,084
The AsymSafe conference starts tomorrow. Some new titles of talks have been added to the list, and some of the speakers have posted abstracts. Smolin's was interesting, I thought. I'm curious to know what Rivasseau is proposing as a mechanism that could underlie and cause Asymptotic Safety.

I have highlighted Rahmede's talk because he is reporting joint work with Roberto Percacci and others. The corresponding papers have just been posted on arxiv. It is possible that Rahmede's talk will cover among the most valuable recent results reported at the conference. So I highlighted those three.

Here's an updated list that includes abstracts of some talks:

Jan Ambjorn, Utrecht University
CDT and asymptotic safety
CDT is a lattice regularization of quantum gravity. The phase structure of the lattice theory is discussed and a candidate UV fixed point located.

Alfio Bonanno, INAF, Catania
The mass-inflation phenomenon in the asymptotic safety scenario

John Joseph M. Carrasco, UCLA
Perturbative cancellations in gravity theories
I will present recent results through four loops demonstrating that the maximally supersymmetric (N=8) generalization of gravity is surprisingly well behaved in the ultraviolet as a result of unexpected cancellations between contributing terms. These cancellations first manifest at one loop in the form of the "no-triangle property," with all-loop order implications through unitarity. I will conclude by discussing similar novel cancelations identified in pure Einstein gravity, at one loop, which suggest a possible explanation for the unexpectedly tame high energy behavior of N=8 supergravity beyond the limited UV protection of supersymmetry.

Holger Gies, ITP, Jena University
Mechanisms of Asymptotic Safety

Renate Loll, Utrecht University
Nonperturbative Insights from Causal Dynamical Triangulations

Max Niedermaier, Tours University
Gravitational fixed points and asymptotic safety from perturbation theory

Christoph Rahmede, Jena University
Renormalization Group Flow in Scalar-Tensor Theories

Martin Reuter, Mainz University
Gravitational average action and asymptotic safety: past and future

Vincent Rivasseau, Université Paris-Sud XI, Orsay
A New Mechanism for Asymptotic Safeness

Frank Saueressig, Mainz University
Exploring the Theory Space of Asymptotically Safe Quantum Gravity

Michael Scherer, ITP, Jena University
A mechanism for Asymptotic Safety of chiral Yukawa systems
We will discuss Weinberg's idea of asymptotic safety for a chiral Yukawa system with a U(N_L)_L x U(1)_R symmetry in a leading-order derivative expansion using nonperturbative functional RG equations. As a toy model sharing important features with the standard model we explicitely discuss N_L=10 for which we find a non-Gaussian fixed point and compute its critical exponents. We observe a reduced hierarchy problem and obtain predictions for the toy Higgs and the toy top mass.

Lee Smolin, Perimeter Institute
Asymptotic safety and deformed symmetry
I review work on asymptotic safety in quantum gravity in a 1/N expansion. I highlight the result that the scaling behavior governed by the non-trivial fixed point must be characterized by a scaling dimension less than four. Otherwise a Weyl curvature squared counterterm is required, that renders the theory unstable. This reduced scaling dimension then implies that Lorentz invariance is either broken or deformed, and this is transmitted to the matter sector. However, there are strong constraints on breaking of Lorentz invariance at the Planck scale due to the absence of birefringence of photons. The present constraints on deforming Lorentz invariance are, however, just at the Planck scale. I will then review semiclassical quantum gravity arguments that Lorentz symmetry is deformed.


Arkady Tseytlin, Imperial College, London
Comments on UV divergences in quantum gravity

Gian Paolo Vacca, Bologna University
Quantum Gravitational Corrections to Matter: A Running Controversy

B.F.L. Ward, Baylor University
Asymptotic Safety and Resummed Quantum Gravity
In Weinberg’s asymptotic safety approach to quantum gravity, one has a finite dimensional critical surface for a UV stable fixed point to generate a theory of quantum gravity with a finite number of physical parameters. The task is to demonstrate how this fixed point behavior actually arises. We argue that, in a recently formulated extension of Feynman’s original formulation of the theory, which we have called resummed quantum gravity, we recover this fixed-point UV behavior from an exact re-arrangement of the respective perturbative series. We argue that the results we obtain are consistent both with the exact field space Wilsonian renormalization group results of Reuter and Bonanno and with recent Hopf-algebraic Dyson-Schwinger renormalization theory results of Kreimer. We calculate the first "first principles" predictions of the respective dimensionless gravitational and cosmological constants and argue that they support the Planck scale cosmology advocated by Bonanno and Reuter as well. Comments on the prospects for actually predicting the currently observed value of the cosmological constant are also given.

Steven Weinberg, University of Texas, Austin
Prospects for Asymptotic Safety

Omar Zanusso, SISSA
Asymptotic safety in the nonlinear sigma models and gravity

Jean Zinn-Justin, CEA, Saclay
Asymptotic safety: a review
I shall review on field theory examples, the meaning of the concept of asymptotic safety in the context of low energy effective field theories.

---from the webpage http://www.perimeterinstitute.ca/en/...ety/Abstracts/
MTd2
#205
Nov4-09, 09:30 PM
PF Gold
P: 1,955
BTW, have you noticed what means to Carrasco go to this conference?

BTW, let me guess, the paper in which Vincent Rivasseau will base his talk is this one:
http://arxiv.org/abs/0906.5477
MTd2
#206
Nov4-09, 09:42 PM
PF Gold
P: 1,955
Horava Gravity conference starts in the same day Asymptotic Safety ends:

http://www.perimeterinstitute.ca/en/...arbagez_Point/
atyy
#207
Nov4-09, 10:08 PM
Sci Advisor
P: 8,317
Quote Quote by MTd2 View Post
BTW, have you noticed what means to Carrasco go to this conference?
Yes, I'm very curious whether his results are at all related to AS. Gping by Percacci's GraviGUT, maybe we can soon have an AS landscape too.
MTd2
#208
Nov4-09, 10:21 PM
PF Gold
P: 1,955
BTW, time to include this guy, B.F.L Ward, on the thread of Rovelli's program:

Resumed gravity:

http://arxiv.org/find/gr-qc/1/au:+Ward_B/0/1/0/all/0/1

I didn't know this guy, but I got hints of this idea in other papers, and posted it here

http://www.physicsforums.com/showpos...9&postcount=20

"[...]it is not just the physicists' trying to dig something out of diagrams. It is the couplings of the theory dynamically cooperating and organizing somehow among themselves to find a point stable in a surface, all this which ends up causing the renormalization of the theory."

EDIT.: I guess I really did read about him, I just forgot, here's more of his papers:

http://www.slac.stanford.edu/spires/...ea+Ward,+B+F+L
marcus
#209
Nov11-09, 02:44 PM
Astronomy
Sci Advisor
PF Gold
marcus's Avatar
P: 23,084
RUTA recently contributed another link to add to our list of 4D quantum gravity links to keep handy for reference.
Workshops at Ashtekar's Penn State IGC:
http://www.gravity.psu.edu/events/workshops.shtml
Past talks of the International LQG Seminar, online.
http://relativity.phys.lsu.edu/ilqgs/

September 2009 Corfu QG School (so far audio has been posted for only a small portion)
http://www.physics.ntua.gr/corfu2009/qg.html
http://www.physics.ntua.gr/corfu2009...eekSchool.html

June 2009 school for Nonperturbative Gravity and QCD at Zakopane. Online media incomplete.
http://th-www.if.uj.edu.pl/school/2009/
http://th-www.if.uj.edu.pl/school/2009/lectures.html

June 2009 PlanckScale conference video and slides:
http://www.ift.uni.wroc.pl/~planckscale/
http://www.ift.uni.wroc.pl/~planckscale/movie/
http://www.ift.uni.wroc.pl/~rdurka/p...ndex-video.php

July 2009 Marcel Twelve conference in Paris (886 participants):
http://www.icra.it/MG/mg12/en/
http://www.icra.it/MG/mg12/talks_plenary/Freidel.pdf

Loops 2009 in Beijing (~230 participants)
http://www.mighty-security.com/loop/timetable1.htm

August 2009 EG4 at Vancouver. No online media so far.
http://www.emergentgravity.org/index..._programme.php

November 2009 Asymptotic safety conference at Perimeter:
http://www.perimeterinstitute.ca/en/...0_Years_Later/
AsymSafe videos:
http://pirsa.org/C09025
November 2009 Horava gravity videos:
http://pirsa.org/C09026

June 2010 Americas QG school at Morelia
http://www.physics.ucsb.edu/~pasi/

July 2010 GR19 conference in Mexico City
http://www.gr19.com/index.php

Links to check for new announcements:
http://www.maths.nottingham.ac.uk/qg/
http://grg.maths.qmul.ac.uk/hyperspace/conference/
http://grg.maths.qmul.ac.uk/hyperspa...ce/latest.html

Topcited Loop papers after 2006 (keywords SPIN FOAM, GROUP FIELD THEORY, LOOP QUANTUM COSMOLOGY, LOOP QUANTUM GRAVITY):
http://www.slac.stanford.edu/spires/...tecount%28d%29

Some classic online sources:
Rovelli's talk at Strings 2008 Video
http://cdsweb.cern.ch/record/1121957?ln=en
Slides
http://indico.cern.ch/getFile.py/acc...s&confId=21917
2003 draft of Rovelli's book online
http://www.cpt.univ-mrs.fr/%7Erovelli/book.pdf
Rovelli's chapter in Oriti's book
http://arxiv.org/abs/gr-qc/0604045
Review of LQG as of May 2008:
http://relativity.livingreviews.org/...es/lrr-2008-5/
Steven Weinberg's 6 July talk, main CERN link:
http://indico.cern.ch/conferenceDisplay.py?confId=57283
Weinberg video:
http://cdsweb.cern.ch/record/1188567/
To save time jump to minute 58, the last 12 minutes.
Photos from the first Loops conference, at Marseille 2004
http://math.ucr.edu/home/baez/marseille/
Longshots:
Vincent Rivasseau at the 2009 Perimeter AsymSafe conference.
http://pirsa.org/09110049/
Ted Jacobson at the 2009 Perimeter HorGrav conference.
http://pirsa.org/09110066/
Krasnov 2006 video lecture
http://pirsa.org/06110041/
Krasnov 2008 audio+pdf talk at the ILQGS
http://relativity.phys.lsu.edu/ilqgs/krasnov020508.pdf
http://relativity.phys.lsu.edu/ilqgs/krasnov020508.aif
marcus
#210
Nov12-09, 04:35 PM
Astronomy
Sci Advisor
PF Gold
marcus's Avatar
P: 23,084
The list of upcoming conferences known as "hyperspace" has moved.
http://hyperspace.aei.mpg.de/category/Conferences/
marcus
#211
Nov21-09, 01:43 PM
Astronomy
Sci Advisor
PF Gold
marcus's Avatar
P: 23,084
Four authors have posted major papers since the last time I updated this short list of sources to keep handy. Steven Weinberg, Roberto Percacci, Kirill Krasnov, and Thomas Thiemann.

http://arxiv.org/abs/0911.3165
Asymptotically Safe Inflation
Steven Weinberg
Discussion: http://physicsforums.com/showthread.php?t=355757

http://arxiv.org/abs/0910.5167
Gravity from a Particle Physicist's perspective
R. Percacci
http://arxiv.org/abs/0911.0386
Renormalization Group Flow in Scalar-Tensor Theories. I
Gaurav Narain, Roberto Percacci
Discussion: http://physicsforums.com/showthread.php?t=349513

http://arxiv.org/abs/0911.3793
Gravity-Yang-Mills-Higgs unification by enlarging the gauge group
Alexander Torres-Gomez, Kirill Krasnov (University of Nottingham)
Discussion: http://physicsforums.com/showthread.php?t=356492

http://arxiv.org/abs/0911.3433
Canonical path integral measures for Holst and Plebanski gravity. I. Reduced Phase Space Derivation
Jonathan Engle, Muxin Han, Thomas Thiemann
Discussion: http://physicsforums.com/showthread.php?t=356264
marcus
#212
Dec15-09, 09:25 PM
Astronomy
Sci Advisor
PF Gold
marcus's Avatar
P: 23,084
Time to do some housekeeping on this list of 4D quantum gravity links to keep handy.

The list of upcoming conferences known as "hyperspace" has moved to the AEI site.
http://hyperspace.aei.mpg.de/category/Conferences/

June 2009 PlanckScale conference video and slides:
http://www.ift.uni.wroc.pl/~planckscale/
http://www.ift.uni.wroc.pl/~planckscale/movie/
http://www.ift.uni.wroc.pl/~rdurka/p...ndex-video.php

RUTA pointed out these workshops at Ashtekar's Penn State IGC:
http://www.gravity.psu.edu/events/workshops.shtml

Past talks of the International LQG Seminar, online:
http://relativity.phys.lsu.edu/ilqgs/

July 2009 Marcel Twelve conference in Paris (886 participants):
http://www.icra.it/MG/mg12/en/
http://www.icra.it/MG/mg12/talks_plenary/Freidel.pdf

Loops 2009 in Beijing (~230 participants):
http://www.mighty-security.com/loop/timetable1.htm

November 2009 Asymptotic safety conference at Perimeter:
http://www.perimeterinstitute.ca/en/...0_Years_Later/
AsymSafe videos:
http://pirsa.org/C09025
November 2009 Horava gravity videos:
http://pirsa.org/C09026

June 2010 Americas QG school at Morelia:
http://www.physics.ucsb.edu/~pasi/

July 2010 GR19 conference in Mexico City:
http://www.gr19.com/index.php

Nottingham QG network:
http://www.maths.nottingham.ac.uk/qg/

Topcited Loop papers after 2006
(keywords "spin, foam", "field theory, group", "quantum gravity, loop space", and "quantum cosmology, loop space"):
http://www.slac.stanford.edu/spires/...tecount%28d%29

Classic online sources.
Rovelli's talk at Strings 2008 Video:
http://cdsweb.cern.ch/record/1121957?ln=en
Slides:
http://indico.cern.ch/getFile.py/acc...s&confId=21917
2003 draft of Rovelli's book online:
http://www.cpt.univ-mrs.fr/%7Erovelli/book.pdf
Rovelli's chapter in Oriti's book:
http://arxiv.org/abs/gr-qc/0604045
Review of LQG as of May 2008:
http://relativity.livingreviews.org/...es/lrr-2008-5/
Steven Weinberg's 6 July talk, main CERN link:
http://indico.cern.ch/conferenceDisplay.py?confId=57283
Weinberg video (historical overview up to minute 58 followed by
no-frills approach to unification in the last 12 minutes):
http://cdsweb.cern.ch/record/1188567/
Related Weinberg paper Asymptotically Safe Inflation:
http://arxiv.org/abs/0911.3165
Discussion thread http://physicsforums.com/showthread.php?t=355757
Roberto Percacci's Gravity from a Particle Physicist's Perspective:
http://arxiv.org/abs/0910.5167
Narain and Percacci Renormalization Group Flow in Scalar-Tensor Theories. I:
http://arxiv.org/abs/0911.0386
Discussion thread http://physicsforums.com/showthread.php?t=349513

Photos from the first Loops conference, at Marseille 2004:
http://math.ucr.edu/home/baez/marseille/

Selected longshots.
Vincent Rivasseau at the 2009 Perimeter AsymSafe conference:
http://pirsa.org/09110049/
Ted Jacobson at the 2009 Perimeter HorGrav conference:
http://pirsa.org/09110066/
Krasnov 2006 video lecture:
http://pirsa.org/06110041/
Krasnov 2008 audio+pdf talk at the ILQGS:
http://relativity.phys.lsu.edu/ilqgs/krasnov020508.pdf
http://relativity.phys.lsu.edu/ilqgs/krasnov020508.aif
Krasnov and Gomez Gravity-Yang-Mills-Higgs unification by enlarging the gauge group:
http://arxiv.org/abs/0911.3793
marcus
#213
Dec28-09, 06:02 PM
Astronomy
Sci Advisor
PF Gold
marcus's Avatar
P: 23,084
It could be that there will be no Loops 2010 conference, no big international QG meeting.
I've heard nothing about one being organized. On the other hand, I have heard of other comparable or related events:

Sabine Hossenfelder is organizing a Stockholm workshop on the experimental search for QG.
http://backreaction.blogspot.com/200...m-gravity.html
Here's the website:
http://th.physik.uni-frankfurt.de/~hossi/ESQG10/
This will take place 12-16 July.

Then there is this two-week-long PASI QG school, with lecture-series by Abhay Ashtekar, Carlo Rovell, Laurent Freidel, Renate Loll...
PASI stands for "Panamerican Advanced Studies Institute". The school will be supported by the US National Academy of Sciences. In a way that is even better than having a Loops conference (in terms of some obvious practical goals.) Here is the 2010 QG School website:
http://www.physics.ucsb.edu/~pasi/
This will take place 23 June-3 July.

Thanks to 'Sabah for mentioning the Experimental QG Search workshop. The website already shows an impressive list of QG people who will be participating.

Also being held in 2010 is the 19th international General Relativity and Gravitation conference, GR19. This is a major conference held every three years, bringing all gravity related research programs together. One of the parallel sessions will be devoted to Loop.
http://www.gr19.com/index.php
This will take place 5-9 July.

So things will be happening with some resemblance to an annual meeting, but as far as I know no official Loops 2010 has been announced.

Here's the website for Strings 2010, in case anyone is interested.
http://mitchell.physics.tamu.edu/Conference/string2010/
It will take place 15-19 March.
guedes
#214
Dec30-09, 09:29 AM
P: 3
I think it's good to point out the upcoming Quantum Gravity school held in Zakopane taking place 28 February - 4 March. This year the main topic is Open problems in Loop Quantum Gravity and it seems to be quite interesting as a way to settle future directions. The programme (and registration - still opened!) here:
http://www.fuw.edu.pl/~jpa/qgqg3/

*Notice*
At the end of the Loops'09 conference it was announced that there won't be any Loops'10 precisely because of GR19. And so, the next one is Loops'11 to be held in Madrid, Spain.
marcus
#215
Jan4-10, 06:32 PM
Astronomy
Sci Advisor
PF Gold
marcus's Avatar
P: 23,084
It's often informative to note the focus of the year's workshops, conferences and schools. Can give an idea about the direction things are going. This year there will be two QG schools (when I started watching in 2003 there were no annual Loop conferences and no QG schools at all.) This year there will also be a workshop on search for observable effects--QG phenomena.

The programs for the year's meetings are mosty not posted yet, but here are links to the websites that we can watch for information as it appears.

QGQG3, The third European QG school, 28 February - 4 March
http://www.fuw.edu.pl/~jpa/qgqg3/

Panamerican QG School, the first such supported by the US, 23 June - 3 July
http://www.physics.ucsb.edu/~pasi/

GR19, the triennial international meeting on General Rel and Gravitation, 5 - 9 July
http://www.gr19.com/index.php

Workshop on the Experimental Search for Quantum Gravity, 12 - 16 July
http://th.physik.uni-frankfurt.de/~hossi/ESQG10/

There will be a session of GR19 devoted to loop and spinfoam quantum gravity. This will serve as the main international LQG conference this year so there will be no separate Loops 2010, as Guedes tells us. He also says Loops 2011 will be held in Madrid.
marcus
#216
Jan25-10, 08:11 PM
Astronomy
Sci Advisor
PF Gold
marcus's Avatar
P: 23,084
In an earlier post I had a bad link to the slides for Rovelli's Strings 2008 talk.
Here are the (in one case repaired) links
Video:
http://cdsweb.cern.ch/record/1121957?ln=en
Slides:
http://indico.cern.ch/getFile.py/acc...s&confId=21917


Register to reply

Related Discussions
A First Course in Loop Quantum Gravity Beyond the Standard Model 23
Loop Quantum Gravity? Beyond the Standard Model 7
Loop quantum gravity Beyond the Standard Model 9
Loop quantum gravity Beyond the Standard Model 71
Loop quantum gravity General Physics 13