Quantum gravity Definition and 470 Threads

If you follow QG research you will remember that in September 2009 there was a mainly Loop QG school/workshop on Corfu at which several people presented minicourses (John Baez, Carlo Rovelli, Abhay Ashtekar, Vincent Rivasseau, John Barrett...) Each minicourses was a series of 5 onehour lectures...

The paper below suggests an alternative to dark matter, the strength of gravity is greater than is predicted by GR due to graviton-graviton self-interactions in regions of higher density of matter. Hence dark matter is unnecessary. The increase would be too small to be measured locally, hence...

What are the chances that a guy can get a graduate position studying LQG, and a job after that?

hi, how can we be sure that quantum gravity effects appear only at the Planck scale? when i look at the quantum mechanics effects, there seem to be a relationship with general relativity so both could be the same phenomena . i thought that the aim of quantum gravity is to find out the...

hi, what do you think of the Penrose interpretation of quantum gravity, that gravity is responsible of the transitions between the quantum world and the macroscopic world?

Is there a list somewhere here of the seminal papers in quantum gravity? I recently ran across a paper/chapter by Ashtekar: Non-perturbative Quantum Gravity: What and Why? from a 1991 book Lectures on non-perturbative canonical gravity by Abhay Ashtekar, Ranjeet S. Tate when googling to find...

I keep seeing references to UV and IR in references to string theory and quantum gravity. This seems to come up in discussions of renormalization especially. Can someone please explicitly explain the term? Google doesn't seem to help here. There are way too many references. I have tried...

http://prime-spot.de/ESQG10/program.html Comments: http://backreaction.blogspot.com/2010/10/experimental-search-for-quantum-gravity.html

Recently I started a new thread regarding Gribov (gauge fixing) ambiguities in quantum field theory, especially in QCD https://www.physicsforums.com/showthread.php?t=429759. Of course every theory incorporating a local gauge symmetry may have this gauge fixing issue - therefore in GR and all...

Feynman very clearly presented QED in his book The strange theory of light and matter. He tried also with quantum gravity calculations. But, how to clearly present, why his calculations did not lead to quantum gravity.

So basically I am about to embark on my Msc in the pure maths department. Now I wish to conduct research on the subject of arithmetic quantum chaos and its applications in number theory and in gravity and cosmology. In my university I found someone who is an expert in its applications to...

I have a discussion witrh a colleague regarding the ADM formalism and foliation independence. My argument goes as follows: once I have chosen one (arbitrary) foliation the theory has two constraints H and D. H ~ 0 guarantuess that physical states do not change in coordinate-time, so physics...

http://arxiv.org/abs/1006.0199 From twistors to twisted geometries Laurent Freidel, Simone Speziale 9 pages (Submitted on 1 Jun 2010) "In a previous paper we showed that the phase space of loop quantum gravity on a fixed graph can be parametrized in terms of twisted geometries, quantities...

I've got a bachelors in Ephys and I'm REALLY interested in quantum gravity (LQG and semi-classical approaches), but my GR experience is limited to running a few simulations in Mathematica, and I've just had the first semester of QM. I know it's not realistic to start doing QG right away with...

http://en.wikipedia.org/wiki/Quantum_gravity Is Quantum Gravity considered to be beyond the Standard Model? Why or why not? What are the implications of Quantum Gravity, and the possibility of a dynamic aether? What are the practical means for investigating Quantum Gravity? Is Atom...

Hi, has anybody studied the papers from Eyo Eyo Ita III? E.g. recently http://arxiv.org/abs/0805.4004v3 Canonical quantization of Plebanski gravityEyo Eyo Ita III (Submitted on 26 May 2008 (v1), last revised 30 Apr 2010 (this version, v3)) Abstract: In this paper we show that the...

http://arxiv.org/abs/1004.1780 A new look at loop quantum gravity Carlo Rovelli 15 pages, 5 figures (Submitted on 11 Apr 2010) "I describe a possible perspective on the current state of loop quantum gravity, at the light of the developments of the last years. I point out that a theory is...

Are there any "graphene" Planck-scale quantum gravity? I'm wondering if there is any QG or emergent structure that is "graphene" due to suggestions from this paper, specifically, does LQG, SF, CDT,M-theory, etc., suggest space consists of discrete points arranged in a non-cubic lattice...

hi,if someone work in quantum gravity exactly in bohmienne quantum gravity then help me with documentations in the subject because i need it a lot . And if you know how to get the "physics review,letter " articles gratis tell me .thanks

Hey I'm writing a paper on the problems that arise between general relativity and quantum mechanics and was wondering if anyone had any good recommendations on the topic in terms of books? I'm not looking for textbooks that delve into all of the mathematics of string theory or anything like...

Hi there! Just asking for a website with a detailed list of winter/summer schools, workshops and so on for the full present year, related with quantum gravity. Thank you very much in advance.

Are quantum gravity theories trying to progress on the assumption that there are such things as gravitons?

as I know, they both explain about how gravitation work. But how they different? which one is the most correct?

Might BEC give insight into how quantum gravity works? comment? Laura

explanation of word "foliation" in quantum gravity? I please for explanation of word "foliation" in quantum gravity?

Hello everyone, does anybody of you know, whether there are some publications/blog entries/ideas/anything on possibilities of experimental verification/falsification of Loop Quantum Gravity at collider experiments? I know, there are predictions that can be tested with astrophysical...

De Sitter Relativity: a New Road to Quantum Gravity http://www.springerlink.com/content/g6275857g60638h8/fulltext.pdf ...When applied to the whole universe, de Sitter special relativity is able to predict,from the current matter content of the universe, the value of cosmological constant...

Lecture 1: http://pirsa.org/10010094/ (25 January) Lecture 2: http://pirsa.org/10010095/ (26 January) Lecture 3: http://pirsa.org/10010096/ (27 January) Lecture 4: http://pirsa.org/10010097/ (28 January) This is planned as a three-week series of one-hour lectures. She does not use slides...

Hello all, I'm just wondering, have physicists come up with an accepted theory for quantum gravity?

The logic of spin-2 gravitons is that GR predicts gravitational waves, and in QM, all waves are also particles. Gravitational waves are seen as waves of spacetime whereas gravitons are mediated as particles on fixed spacetime. Spin-2 gravitons can reproduce GR using QFT in the weak field...

Has anybody studied this paper? http://arxiv.org/abs/0909.0212v4 Comprehensive Solution to the Cosmological Constant, Zero-Point Energy, and Quantum Gravity Problems Philip D. Mannheim (Submitted on 1 Sep 2009 (v1), last revised 7 Jan 2010 (this version, v4)) Abstract: We present a...

Since there are several people here who intently follow the developements of LQG, I was wondering if someone could give some overview to help understand the 'historical path' of research on this topic better. What methods were developed, which died off, what was learned, where they are going...

Kaku is famous for promoting string/M-theory in a variety of books from hyperspace to physics of impossible, to name a few. He also popularizes string theory in radio and sci-fi documentaries. He was asked what he thought of loop quantum gravity: Antimatter How much closer are we at this...

There has at times been expressions of hope that a theory of quantum gravity may help resolve issues such as the 'measurement problem' in quantum mechanics (Penrose, and Smolin I think, and probably others). Have any of the recent 'advances'/'new lines of study' towards a quantum theory of...

Has anyone seen this? Can you say how well it fits into the popularization of 4D Quantum Gravity picture? Whether it presents a clear popular account of Loop Cosmology? I just checked German Amazon and found this: Zurück vor den Urknall: Die ganze Geschichte des Universums von Martin...

Have loop quantum theorists looked forward to how one might fit the standard model into loop quantum gravity? Thank you for any help.

Hi there, I am currently doing a project on LQG and I am having troubles grasping the basics. I am just wondering if anyone here could help answer a couple of questions that I have during my study. 1.) How to use Roger Penrose's original spin-network? I read in his book that they are used to...

At what level (graduate, PhD, etc...) do people start learning theories, such as String Theory and Loop Quantum Gravity?

Ok, I've been trying to follow what you guys have written about this. Is it sort of like protein folding in biology, only instead of proteins you have space time, and you spin it around, and most of it is quantum foam vacuum stuff, but in some places it clumps in sort of oscillating ways...

The Coming Revolutions in Fundamental Physics--as seen by string-master David Gross http://seminput.aei.mpg.de/more_info.php?which=2478&talk=index ==quote== Max-Planck-Institut für Gravitationsphysik, Albert-Einstein-Institut The Coming Revolutions in Fundamental Physics Wed 7 Oct 2009...

hi,if someone work in quantum gravity exactly in bohmienne quantum gravity then help me with documentations in the subject because i need it a lot . And if you know how to get the "physics review,letter " articles gratis tell me .thanks

I was browsing a list of recently published papers on arxiv.org, and I found this paper: Comprehensive Solution to the Cosmological Constant, Zero-Point Energy, and Quantum Gravity Problems Authors: Philip D. Mannheim arXiv:0909.0212 Here's the abstract: "We present a solution to...

I have just seen this: http://www.fma.if.usp.br/~rivelles/Rede_Tematicos/workshop.html NEW TRENDS IN QUANTUM GRAVITY II Rede Sul-Americana de Gravitação Quântica September 8 to 11, 2009 Instituto de Física Teórica - São Paulo, Brazil SPEAKERS * G. Aldazabal (C. A...

Is somebody here involved with the causal set approach to QG? http://arxiv.org/abs/gr-qc/0309009 is a nice introduction to the theme, and I liked among the introduction with some quotes of Riemann. If so or any of the good people like to give opinion, I would like to make some questions...

So, a couple weeks ago I read this article. I came here, expecting that someone would probably talk about it (I've been viewing posts here for a while, but became a member only recently). No one, that I could find, has actually talked about it, so I though it would be a good first post for me...

Let's suppose gravitons exist, and you have a machine that is 100% effective at detecting them. If you were in a room with no windows, and there is an apparent gravitational field, then would using this machine let you tell if you were in a gravitational field or accelerating?

I watched a seminar in particle physics and they mentioned that it was difficult to reconcile general relativity and Quantum field theory, I was just curious as to why it was so difficult considering quantum field theory is already reconciled with special relativity and gauge symmetry. what...

confused about quantum gravity theory? I know that quantum gravity is used to describe the effects of the gravitational interaction under differentg circumstandes, But can anyone please explain,under what circumstances is the theory appropriate, also some examples of the phenomena that are...

In the LQG theory does the universe have to be closed, or can space be infinite in size? What I mean is, is the LQG theory similar to the quasi steady state theory in which the universe does collapse, and then bounces back, but is still infinite in size.

Interesting that Steven Weinberg should cite Asymptotic Safety work by Martin Reuter and Frank Saueressig. And another UV-safety article by Roberto Percacci, that appears in Oriti's new book Approaches to Quantum Gravity: Towards a New Understanding of Space, Time, and Matter. Here's a bit...