Register to reply 
Introduction To Loop Quantum Gravityby marlon
Tags: loop quantum gravity 
Share this thread: 
#199
Oct1809, 08:08 PM

Astronomy
Sci Advisor
PF Gold
P: 23,121

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.mightysecurity.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 (84) 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 audioonly 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.mightysecurity.com/loop/timetable1.htm http://www.mightysecurity.com/loop/timetable2.htm http://www.mightysecurity.com/loop/timetable3.htm http://www.mightysecurity.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 "waigworen" friendly, so I bailed. I think waigwo 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. 


#200
Oct2309, 11:47 AM

Astronomy
Sci Advisor
PF Gold
P: 23,121

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 cosmologyearly 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 9:209:30 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 ZinnJustin, 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 9:3010:30 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 3:004:00 PM Frank Saueressig, Mainz University TBA 4:306:00 PM TBA 6:00PM Banquet Dinner Saturday, November 7, 2009 9:3010:30 AM Arkady Tseytlin, Imperial College, London Comments on UV divergences in quantum gravity 11:00AM – 12:00 PM Vincent Rivasseau, Universite ParisSud XI, Orsay TBA 2:00 – 3:00 PM Alfio Bonanno, INAF, Catania The massinflation phenomenon in the asymptotic safety scenario 3:004:00 PM John Joseph M. Carrasco, UCLA Perturbative cancellations in gravity theories 4:306:00PM 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 timeslot: Michael Scherer FriedrichSchillerUniversität 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 cosmologysome 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://thwww.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 


#201
Oct2509, 11:49 AM

Astronomy
Sci Advisor
PF Gold
P: 23,121

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 SpinFoams 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 19941998. 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/grqc/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/grqc/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/grqc/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 spinnetworkwithout 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 hocit 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 reunderstand 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 EngleLivine PereiraRovelli, and see how the technical numbers like the angular momentum "j" symbols arise. Lewandowski has been a major force in making Loopandrelated 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 5hour 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 


#202
Oct2509, 01:03 PM

Sci Advisor
P: 8,393

http://arxiv.org/abs/0909.0939
v1. The second paper we appreciate so much is the derivation of the new spinfoam model from the Holst action by Engle, Livine, Pereira and Rovelli [6]. Those two excellent works brought spinfoams closer to LQG. On the other hand, we regret have not considered here closer the FreidelKrasnov model [12]. v2. The second paper we appreciate so much is the derivation of the new spinfoam model from the Holst action by Engle, Livine, Pereira and Rovelli [6]. Those two excellent works brought spinfoams 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 FreidelKrasnov 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. 


#203
Oct3109, 02:00 PM

Astronomy
Sci Advisor
PF Gold
P: 23,121

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 9:209:30 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 ZinnJustin, 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 9:3010:30 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 3:004:00 PM Frank Saueressig, Mainz University Exploring the Theory Space of Asymptotically Safe Quantum Gravity 4:305:00 PM Elisa Manrique, Mainz University TBA 5:005:30 PM Christophe Rahmede, University of Sussex TBA Saturday, November 7, 2009 9:3010:30 AM Arkady Tseytlin, Imperial College, London Comments on UV divergences in quantum gravity 11:00AM – 12:00 PM Vincent Rivasseau, Universite ParisSud XI, Orsay TBA 2:00 – 3:00 PM Alfio Bonanno, INAF, Catania The massinflation phenomenon in the asymptotic safety scenario 3:004:00 PM John Joseph M. Carrasco, UCLA Perturbative cancellations in gravity theories 4:305:00PM Gian Paolo Vacca, INFN, Bologna TBA 5:005:30PM 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://thwww.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 


#204
Nov409, 07:30 PM

Astronomy
Sci Advisor
PF Gold
P: 23,121

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 massinflation 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 "notriangle property," with allloop 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 ScalarTensor Theories Martin Reuter, Mainz University Gravitational average action and asymptotic safety: past and future Vincent Rivasseau, Université ParisSud 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 leadingorder 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 nonGaussian 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 nontrivial 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 fixedpoint UV behavior from an exact rearrangement 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 Hopfalgebraic DysonSchwinger 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 ZinnJustin, 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/ 


#205
Nov409, 09:30 PM

PF Gold
P: 1,960

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 


#206
Nov409, 09:42 PM

PF Gold
P: 1,960

Horava Gravity conference starts in the same day Asymptotic Safety ends:
http://www.perimeterinstitute.ca/en/...arbagez_Point/ 


#207
Nov409, 10:08 PM

Sci Advisor
P: 8,393




#208
Nov409, 10:21 PM

PF Gold
P: 1,960

BTW, time to include this guy, B.F.L Ward, on the thread of Rovelli's program:
Resumed gravity: http://arxiv.org/find/grqc/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 


#209
Nov1109, 02:44 PM

Astronomy
Sci Advisor
PF Gold
P: 23,121

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://thwww.if.uj.edu.pl/school/2009/ http://thwww.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...ndexvideo.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.mightysecurity.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.univmrs.fr/%7Erovelli/book.pdf Rovelli's chapter in Oriti's book http://arxiv.org/abs/grqc/0604045 Review of LQG as of May 2008: http://relativity.livingreviews.org/...es/lrr20085/ 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 


#210
Nov1209, 04:35 PM

Astronomy
Sci Advisor
PF Gold
P: 23,121

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


#211
Nov2109, 01:43 PM

Astronomy
Sci Advisor
PF Gold
P: 23,121

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 ScalarTensor Theories. I Gaurav Narain, Roberto Percacci Discussion: http://physicsforums.com/showthread.php?t=349513 http://arxiv.org/abs/0911.3793 GravityYangMillsHiggs unification by enlarging the gauge group Alexander TorresGomez, 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 


#212
Dec1509, 09:25 PM

Astronomy
Sci Advisor
PF Gold
P: 23,121

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...ndexvideo.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.mightysecurity.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.univmrs.fr/%7Erovelli/book.pdf Rovelli's chapter in Oriti's book: http://arxiv.org/abs/grqc/0604045 Review of LQG as of May 2008: http://relativity.livingreviews.org/...es/lrr20085/ 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 nofrills 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 ScalarTensor 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 GravityYangMillsHiggs unification by enlarging the gauge group: http://arxiv.org/abs/0911.3793 


#213
Dec2809, 06:02 PM

Astronomy
Sci Advisor
PF Gold
P: 23,121

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...mgravity.html Here's the website: http://th.physik.unifrankfurt.de/~hossi/ESQG10/ This will take place 1216 July. Then there is this twoweeklong PASI QG school, with lectureseries 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 June3 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 59 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 1519 March. 


#214
Dec3009, 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. 


#215
Jan410, 06:32 PM

Astronomy
Sci Advisor
PF Gold
P: 23,121

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 effectsQG 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.unifrankfurt.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. 


#216
Jan2510, 08:11 PM

Astronomy
Sci Advisor
PF Gold
P: 23,121

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 