Results 1 to 10 of about 20,657 (67)

The volume operator in covariant quantum gravity [PDF]

, 2010
A covariant spin-foam formulation of quantum gravity has been recently developed, characterized by a kinematics which appears to match well the one of canonical loop quantum gravity.
Alexandrov S, Ashtekar A, Ashtekar A, Ashtekar A, Ashtekar A Campiglia M Henderson A, Baez J C, Barrett J W, Battisti M V Marciano A Rovelli C, Bianchi E Rovelli C Vidotto F, Carlo Rovelli, Engle J, Flori C, Flori C Thiemann T, Freidel L, Iwasaki J, Livine E, Noui K, Oriti D, Pereira R, Perez A, Reisenberger M P, Reisenberger M P, Reisenberger M P, Reisenberger M P, Rovelli C, Rovelli C, Rovelli C, Rovelli C Vidotto F, Smolin L, Thiemann T, You Ding   +30 more
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What is General Relativity? [PDF]

, 2017
General relativity is a set of physical and geometric principles, which lead to a set of (Einstein) field equations that determine the gravitational field, and to the geodesic equations that describe light propagation and the motion of particles on the ...
Coley, Alan A., Wiltshire, David L.
core   +2 more sources

The Geometry of Black Hole singularities [PDF]

, 2014
Recent results show that important singularities in General Relativity can be naturally described in terms of finite and invariant canonical geometric objects. Consequently, one can write field equations which are equivalent to Einstein's at non-singular
Stoica, Ovidiu Cristinel
core   +3 more sources

Quantum Geometry and its Implications for Black Holes [PDF]

, 2006
General relativity successfully describes space-times at scales that we can observe and probe today, but it cannot be complete as a consequence of singularity theorems.
Arnowitt R., Ashtekar A., Bojowald M., Bojowald M., Douglas M., MARTIN BOJOWALD, Nietzsche F., Vereshchagin G. V.   +7 more
core   +2 more sources

Simple quantum cosmology: Vacuum energy and initial state

, 2005
A static non-singular 10-dimensional closed Friedmann universe of Planck size, filled with a perfect fluid with an equation of state with w = -2/3, can arise spontaneously by a quantum fluctuation from nothing in 11-dimensional spacetime.
D. Spergel, D. Youm, E. Elbaz, M. Novello, M. Tegmark, S. Alexander, S. Eidelman, T. R. Mongan, T.R. Mongan   +8 more
core   +2 more sources

Brane-world gravity [PDF]

, 2003
The observable universe could be a 1+3-surface (the "brane") embedded in a 1+3+d-dimensional spacetime (the "bulk"), with standard-model particles and fields trapped on the brane while gravity is free to access the bulk.
Maartens, Roy
core   +3 more sources

Can chaos be observed in quantum gravity?

, 2017
Full general relativity is almost certainly 'chaotic'. We argue that this entails a notion of nonintegrability: a generic general relativistic model, at least when coupled to cosmologically interesting matter, likely possesses neither differentiable ...
Dittrich, Bianca, Hoehn, Philipp A., Koslowski, Tim A., Nelson, Mike I.   +3 more
core   +1 more source

Loop Quantum Gravity: Four Recent Advances and a Dozen Frequently Asked Questions

, 2007
As per organizers' request, my talk at the 11th Marcel Grossmann Conference consisted of two parts. In the first, I illustrated recent advances in loop quantum gravity through examples.
Ashtekar, Abhay
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Relational Motivation for Conformal Operator Ordering in Quantum Cosmology

, 2009
Operator-ordering in quantum cosmology is a major as-yet unsettled ambiguity with not only formal but also physical consequences. We determine the Lagrangian origin of the conformal invariance that underlies the conformal operator-ordering choice in ...
Anderson, Edward
core   +1 more source

Nonmetricity formulation of general relativity and its scalar-tensor extension

, 2018
Einstein's celebrated theory of gravitation can be presented in three forms: general relativity, teleparallel gravity, and the rarely considered before symmetric teleparallel gravity.
Järv, Laur, Rünkla, Mihkel, Saal, Margus, Vilson, Ott   +3 more
core   +1 more source