Results 101 to 110 of about 2,756,107 (244)

Extension of Loop Quantum Gravity to Metric Theories beyond General Relativity

, 2011
The successful background-independent quantization of Loop Quantum Gravity relies on the key observation that classical General Relativity can be cast into the connection-dynamical formalism with the structure group of SU(2).
Ashtekar A, Ashtekar A, Ashtekar A, Fatibene L, Guo H, Han M, Han Y, Thiemann T, Will C M, Yongge Ma, Zhang X, Zhou Z   +11 more
core   +1 more source

Generalized non-local R 2-like inflation

Journal of High Energy Physics, 2023
The R 2 inflation which is an extension of general relativity (GR) by quadratic scalar curvature introduces a quasi-de Sitter expansion of the early Universe governed by Ricci scalar being an eigenmode of d’Alembertian operator.
Alexey S. Koshelev, K. Sravan Kumar, Alexei A. Starobinsky   +2 more
doaj   +1 more source

Dark Energy From the Gravitational Wave Background With Scalar Field Dark Matter

Astronomische Nachrichten, Volume 346, Issue 3-4, March-May 2025.
ABSTRACT Recent observational results, such as those from pulsar timing arrays (PTA), suggest a low‐frequency Gravitational Wave Background (GWB) permeates our universe. This opens the possibility that gravitational waves could span a broader spectrum, potentially impacting cosmological scales.
Edwin L. Pérez‐Ochoa, Tonatiuh Matos
wiley   +1 more source

Degenerate Configurations, Singularities and the Non-Abelian Nature of Loop Quantum Gravity

, 2006
Degenerate geometrical configurations in quantum gravity are important to understand if the fate of classical singularities is to be revealed. However, not all degenerate configurations arise on an equal footing, and one must take into account dynamical ...
Ashtekar A, Ashtekar A, Ashtekar A, Ashtekar A, Ashtekar A, Ashtekar A, Ashtekar A Bojowald M Willis J, Banerjee K, Berger B, Bojowald M, Bojowald M, Bojowald M, Bojowald M, Bojowald M, Bojowald M, Bojowald M, Bojowald M, Bojowald M, Bojowald M, Bojowald M, Bojowald M, Bojowald M, Bojowald M, Bojowald M Hernández H H H Morales-Técotl H A, Bojowald M Morales-Técotl H A, Bojowald M Swiderski R, Brunnemann J, Brunnemann J Thiemann T, Brunnemann J Thiemann T, Brunnemann J Thiemann T, Giesel K Thiemann T, Husain V, Immirzi G, Martin Bojowald, Modesto L, Neville D E, Sahlmann H Thiemann T, Thiemann T, Thiemann T, Willis J   +39 more
core   +1 more source

Stability analysis of Einstein\u27s universe in loop quantum cosmology [PDF]

, 2020
A stability analysis of Einstein’s universe in both classical General Relativity and semiclassical Loop Quantum Cosmology regimes is presented. The stability properties of the General Relativity model are significantly altered due to Loop Quantum Gravity
McCaughey, Eamon
core   +1 more source

Loop Quantum Cosmology

Living Reviews in Relativity, 2008
Quantum gravity is expected to be necessary in order to understand situations in which classical general relativity breaks down. In particular in cosmology one has to deal with initial singularities, i.e., the fact that the backward evolution of a ...
Bojowald Martin
doaj  

Euler–Heisenberg Black Hole Surrounded by Quintessence in the Background of Perfect Fluid Dark Matter: Thermodynamics, Shadows, and Quasinormal Modes

Fortschritte der Physik, Volume 73, Issue 3, March 2025.
Abstract Current observations show that a significant fraction of the Universe is composed of dark energy and dark matter. In this paper, the simultaneous effects of these dark sectors on the Euler–Heisenberg black hole are investigated, using the quintessence matter field and perfect fluid to model them. In particular, the black hole's thermodynamics,
Bilel Hamil, Bekir Can Lütfüoğlu
wiley   +1 more source

Supersymmetric quantum solution for FRW cosmological model with matter [PDF]

Rev.Mex.Fis. 48 (2002) 112-117, 2001
Using technique of supersymmetric quantum mechanics we present new cosmological quantum solution, in the regime for FRW cosmological model using a barotropic perfect fluid as matter field.
arxiv  

Loop Quantum Cosmology

Living Reviews in Relativity, 2005
Quantum gravity is expected to be necessary in order to understand situations where classical general relativity breaks down. In particular in cosmology one has to deal with initial singularities, i.e., the fact that the backward evolution of a classical
Bojowald Martin
doaj  

The effective theory of gravity and dynamical vacuum energy

Journal of High Energy Physics, 2022
Gravity and general relativity are considered as an Effective Field Theory (EFT) at low energies and macroscopic distances. The effective action of the conformal anomaly of light or massless quantum fields has significant effects on macroscopic scales ...
Emil Mottola
doaj   +1 more source