Members have been involved in the organisation of international conferences
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Quantum Gravity

Quantum gravity (QG) is a field of theoretical physics that seeks to describe the force of gravity according to the principles of quantum mechanics.

The current understanding of gravity is based on Albert Einstein's general theory of relativity, which is formulated within the framework of classical physics. On the other hand, the nongravitational forces are described within the framework of quantum mechanics, a radically different formalism for describing physical phenomena based on probability. The necessity of a quantum mechanical description of gravity follows from the fact that one cannot consistently couple a classical system to a quantum one.

Although a quantum theory of gravity is needed in order to reconcile general relativity with the principles of quantum mechanics, difficulties arise when one attempts to apply the usual prescriptions of quantum field theory to the force of gravity. From a technical point of view, the problem is that the theory one gets in this way is not renormalizable and therefore cannot be used to make meaningful physical predictions. As a result, theorists have taken up more radical approaches to the problem of quantum gravity, the most popular approaches being string theory and loop quantum gravity.

Strictly speaking, the aim of quantum gravity is only to describe the quantum behavior of the gravitational field and should not be confused with the objective of unifying all fundamental interactions into a single mathematical framework. Although some quantum gravity theories such as string theory try to unify gravity with the other fundamental forces, others such as loop quantum gravity make no such attempt; instead, they make an effort to quantize the gravitational field while it is kept separate from the other forces. A theory of quantum gravity which is also a grand unification of all known interactions, is sometimes referred to as a theory of everything (TOE).

One of the difficulties of quantum gravity is that quantum gravitational effects are only expected to become apparent near the Planck scale, a scale far smaller in distance (equivalently, far larger in energy) than what is currently accessible at high energy particle accelerators. As a result, quantum gravity is a mainly theoretical enterprise, although there are speculations about how quantum gravity effects might be observed in existing experiments.

This is an excerpt from the article Quantum Gravity from the Wikipedia free encyclopedia. A list of authors is available at Wikipedia.

The current understanding of gravity is based on Albert Einstein's general theory of relativity, which is formulated within the framework of classical physics. On the other hand, the nongravitational forces are described within the framework of quantum mechanics, a radically different formalism for describing physical phenomena based on probability. The necessity of a quantum mechanical description of gravity follows from the fact that one cannot consistently couple a classical system to a quantum one.

Although a quantum theory of gravity is needed in order to reconcile general relativity with the principles of quantum mechanics, difficulties arise when one attempts to apply the usual prescriptions of quantum field theory to the force of gravity. From a technical point of view, the problem is that the theory one gets in this way is not renormalizable and therefore cannot be used to make meaningful physical predictions. As a result, theorists have taken up more radical approaches to the problem of quantum gravity, the most popular approaches being string theory and loop quantum gravity.

Strictly speaking, the aim of quantum gravity is only to describe the quantum behavior of the gravitational field and should not be confused with the objective of unifying all fundamental interactions into a single mathematical framework. Although some quantum gravity theories such as string theory try to unify gravity with the other fundamental forces, others such as loop quantum gravity make no such attempt; instead, they make an effort to quantize the gravitational field while it is kept separate from the other forces. A theory of quantum gravity which is also a grand unification of all known interactions, is sometimes referred to as a theory of everything (TOE).

One of the difficulties of quantum gravity is that quantum gravitational effects are only expected to become apparent near the Planck scale, a scale far smaller in distance (equivalently, far larger in energy) than what is currently accessible at high energy particle accelerators. As a result, quantum gravity is a mainly theoretical enterprise, although there are speculations about how quantum gravity effects might be observed in existing experiments.

This is an excerpt from the article Quantum Gravity from the Wikipedia free encyclopedia. A list of authors is available at Wikipedia.

The article Quantum Gravity at en.wikipedia.org was accessed 15,749 times in the last 30 days. (as of: 06/15/2014)

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Quantum Gravity (Stanford Encyclopedia of…

Quantum Gravity, broadly construed, is a physical theory (still ‘under construction’) incorporating both the principles of general relativity and quantum theory.

plato.stanford.edu/entries/quantum-gravity/

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Quantum gravity - Wikipedia, the free encyclopedia

Quantum Gravity (QG) is a field of theoretical physics that seeks to describe the
force of gravity according to the principles of quantum mechanics. Our current ...

en.wikipedia.org/wiki/Quantum_gravity

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"Quantum Gravity --The Missing Link to Understanding the Evolution ...

Sep 9, 2013 ... Present-day physics cannot describe what happened in the Big Bang. Quantum
theory and the theory of relativity fail in this almost infinitely ...

www.dailygalaxy.com/my_weblog/2013/09/quantum-gravity-the-key-to-the-evolution-of-the-universe.html

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Quantum Gravity - damtp

A site maintained by Cambridge University on advances in quantum theories of gravity.

www.damtp.cam.ac.uk/research/gr/public/qg_home.html

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Quantum Gravity - What is quantum gravity? - Physics - About.com

Quantum Gravity is an attempt to unify Einstein's theory of general relativity with
quantum physics. In essence, it tries to unify the four fundamental forces of ...

physics.about.com/od/quantumphysics/f/quantumgravity.htm

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Physicists Eye Quantum-Gravity Interface: Scientific American

Nov 5, 2013 ... Experiments designed to probe this interface could revitalize a longstanding
quest for a theory of Quantum Gravity.

www.scientificamerican.com/article.cfm?id=physicists-eye-quantum-gravity-interface

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Classical and Quantum Gravity - IOPscience

Classical and Quantum Gravity is an established journal for physicists,
mathematicians and cosmologists in the fields of gravitation and the theory of
spacetime.

iopscience.iop.org/0264-9381/

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Quantum Gravity (Cambridge Monographs on Mathematical Physics ...

Quantum Gravity (Cambridge Monographs on Mathematical Physics) [Carlo
Rovelli] on Amazon.com. *FREE* shipping on qualifying offers. Quantum Gravity ...

www.amazon.com/Quantum-Gravity-Cambridge-Monographs-Mathematical/dp/0521715962

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Loop quantum gravity — Einstein Online

From the point of view of Einstein´s theory, it comes as no surprise that all
attempts to treat gravity simply like one more quantum force (on par with ...

www.einstein-online.info/elementary/quantum/loops

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Quantum Gravity

The title of this post refers to the ongoing dispute situation between Barnes and Noble, the US bookstore retail giant, and Simon & Schuster, publishers.

justinarobson.blogspot.com/

Search results for "Quantum Gravity"

Google: approx. 10.600.000

Quantum Gravity in science

Quantum Gravity - The University of Nottingham

SUMMER SCHOOL New Paths Towards Quantum Gravity

Roskilde University ... Quantum Gravity: An Assessment ... the Summer School
New Paths Towards Quantum Gravity to be held from May 12 to May 16, 2008 in
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List of loop quantum gravity researchers - Wikipedia, the free ...

This is a partial list of notable researchers in the physics field of loop Quantum Gravity. Abhay Ashtekar, Pennsylvania State University, USA; John Baez, ...

Quantum Gravity - damtp

A site maintained by Cambridge University on advances in quantum theories of gravity.

Prof. Dr. Hanno Sahlmann - Institute for Quantum Gravity (Chair for ...

Prof. Dr. Hanno Sahlmann. Contact. Prof. Dr. Hanno Sahlmann University of
Erlangen-Nürnberg Institute for Quantum Gravity Theoretical Physics III Staudtstr.
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Quantum Gravity (Cambridge Monographs on Mathematical Physics ...

Quantum Gravity poses the problem of merging quantum mechanics and ...
Paperback: 488 pages; Publisher: Cambridge University Press (December 17,
2007) ...

Quantum Gravity - Cambridge University Press

Quantum Gravity poses the problem of merging quantum mechanics and general
relativity, the two great conceptual revolutions in the physics of the twentieth ...

Superstrings and Quantum Gravity - University of Sussex

A search for a quantum theory of gravity has for many years proved extremely
difficult with superstring theory offering the only viable candidate. However in ...

[PDF]Loop quantum gravity - Igpg.gravity.psu.edu - Penn State University

Loop Quantum Gravity takes this novel view of the world seriously, by incorpo-
rating the notions of space and time from general relativity directly into quantum ...

PASI on Quantum Gravity - University of California, Santa Barbara

Institute for Mathematics National Autonomous University of Mexico (UNAM),
Morelia, Mexico June 23-July 3, 2010. Lecturers: Abhay Ashtekar (Penn State U.)

Books on the term Quantum Gravity

Quantum Gravity

Quantum Gravity is one of the major "open" problems in theoretical physics, and the loop and spinfoam approach in this book is a major research area in the field.

Quantum Gravity (Cambridge Monographs on Mathematical Physics)

Quantum Gravity poses the problem of merging quantum mechanics and general relativity, the two great conceptual revolutions in the physics of the twentieth century. The loop and spinfoam approach, presented in this book, is one of the leading research programs in the field. The first part of the book discusses the reformulation of the basis of clas...

Quantum Gravity in 2+1 Dimensions

The first comprehensive survey of (2+1)-dimensional Quantum Gravity - for graduate students and researchers.

Three Roads To Quantum Gravity (Science Masters)

The Holy Grail of modern physics is a theory of the universe that unites two seemingly opposing pillars of modern science: Einstein's theory of general relativity, which deals with large-scale phenomena (planets, solar systems and galaxies), and quan

Buddy & Fred: The Adventurous Chronicles

Two good friends Buddy and Fred, have lots of fun together.

A First Course in Loop Quantum Gravity

This book provides an accessible introduction to loop Quantum Gravity and some of its applications, at a level suitable for undergraduate students and others with only a minimal knowledge of college level physics. In particular it is not assumed that the reader is familiar with general relativity and only minimally familiar with quantum mechanics a...

Quantum Gravity

This book presents a self-contained discussion of the concepts, methods and applications that can be expected in such a theory.

Quantum Gravity: Third Edition (International Series of Monographs on Physics)

The search for a quantum theory of the gravitational field is one of the great open problems in theoretical physics. This book presents a self-contained discussion of the concepts, methods and applications that can be expected in such a theory. The two main approaches to its construction -- the direct quantisation of Einstein's general theory ...

Quantum Gravity: Mathematical Models and Experimental Bounds

This book provides the reader with an overview of the different mathematical attempts to quantize gravity written by leading experts in this field. Also discussed are the possible experimental bounds on Quantum Gravity effects.

Foundations of Quantum Gravity

Exploring how the subtleties of quantum coherence can be consistently incorporated into Einstein's theory of gravitation, this book is ideal for researchers interested in the foundations of relativity and quantum physics. The book examines those properties of coherent gravitating systems that are most closely connected to experimental observat...

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Blog posts on the term

Quantum Gravity

Quantum Gravity

Physicists Eye Quantum-Gravity Interface: Scientific American

Experiments designed to probe this interface could revitalize a longstanding quest for a theory of Quantum Gravity

www.scientificamerican.com/article.cfm?id=physicists-eye-quantum-gravity-interface
Quantum Gravity - Important Challenge for Theoretical Physics (13 November 2013)
indico.cern.ch/conferenceDisplay.py?confId=275147

"Quantum Gravity --The Missing Link to Understanding the Evolution of the Universe"

Present-day physics cannot describe what happened in the Big Bang. Quantum theory and the theory of relativity fail in this almost infinitely dense and hot primal state of the universe. Only an all-encompassing theory of Quantum Gravity which unifies these...

www.dailygalaxy.com/my_weblog/2013/09/quantum-gravity-the-key-to-the-evolution-of-the-universe.html
Susskind: String theory not a complete picture of how quantum gravity works | Not Even Wrong

Posted on September 16, 2013 by woit.

www.math.columbia.edu/~woit/wordpress/?p=6252
Quantum steps towards the Big Bang

(Phys.org) —Present-day physics cannot describe what happened in the Big Bang. Quantum theory and the theory of relativity fail in this almost infinitely dense and hot primal state of the universe. Only an all-encompassing theory of Quantum Gravity which unifies these two fundamental pillars of physics ...

phys.org/news/2013-09-quantum-big.html
Backreaction: Quantum Gravity in the Cosmic Microwave Background?

Gravity waves. They are pretty but have
nothing to do with gravitational waves.

backreaction.blogspot.com/2013/10/quantum-gravity-in-cosmic-microwave.html
International Loop Quantum Gravity Seminar: Coarse graining theories

Tuesday, Nov 27th. 2012Bianca Dittrich, Perimeter Institute Title: Coarse graining: towards a cylindrically consistent dynamicsPDF of the talk (14Mb) Audio [.

ilqgs.blogspot.com/2013/11/coarse-graining-theories.html
CFP: Seminar on the Philosophical Foundations of Quantum Gravity | Beyond Spacetime

27-29 September 2013 – University of Illinois at Chicago Invited Speakers: Jeremy Butterfield (Cambridge) Elena Castellani (Florence) Bianca Dittrich (Perimeter Institute) Jeff Harvey (Chicago) Nick Huggett (UIC) Christian Wüthrich (UCSD) The investigation of Quantum Gravity has been central to theoretical physics for at least two decades, but philosophy has only engaged with this field in…

beyondspacetime.net/2013/06/06/cfp-seminar-on-the-philosophical-foundations-of-quantum-gravity/
Physicists Eye Quantum-Gravity Interface | Tracing Knowledge ... Στα ίχνη της Γνώσης

In a strange quantum mechanical effect called “superposition,” the photon simultaneously passes through and reflects backward off the mirror; it then both strikes and doesn’t strike the ball. If quantum mechanics works at the macroscopic level, then the ball will both begin oscillating and stay still, entering a superposition of the two states. Because the…

livasperiklis.com/2013/11/05/httpwp-mep29tmj-56n/
X-ray vision for road diggers: The next quantum leap?

Quantum mechanics has been hailed as the next big thing in technology. And quantum computers are a media favourite. But there is a little-known quantum technology that can peer beneath the earth, which could be ready before the quantum computing revolution comes about.

phys.org/news/2013-11-x-ray-vision-road-diggers-quantum.html
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