Results 71 to 80 of about 458,070 (185)

Generalized Einstein’s Equations from Wald Entropy [PDF]

, 2016
We derive the gravitational equations of motion of general theories of gravity from thermodynamics applied to a local Rindler horizon through any point in spacetime.
Sarkar, Sudipta, Maulik Parikh, Sudipta Sarkar, Parikh, Maulik   +3 more
core   +1 more source

Quantum geometry and gravitational entropy [PDF]

Journal of High Energy Physics, 2007
Most quantum states have wavefunctions that are widely spread over the accessible Hilbert space and hence do not have a good description in terms of a single classical geometry. In order to understand when geometric descriptions are possible, we exploit the AdS/CFT correspondence in the half-BPS sector of asymptotically AdS_5 x S^5 universes.
Simon, Joan, Balasubramanian, Vijay, Czech, Bart Iomiej, Larjo, Klaus, Marolf, Donald   +4 more
openaire   +3 more sources

On relativistic generalization of Perelman’s W-entropy and thermodynamic description of gravitational fields and cosmology [PDF]

, 2017
Using double $$2+2$$ and $$3+1$$ nonholonomic fibrations on Lorentz manifolds, we extend the concept of W-entropy for gravitational fields in general relativity (GR). Such F- and W-functionals were introduced in the Ricci flow theory of three dimensional
Olivia Vacaru, Sergiu I. Vacaru, Vacaru, Olivia, Ruchin, Vyacheslav, Vyacheslav Ruchin, Vacaru, Sergiu I.   +5 more
core   +2 more sources

Gravitational entropy is observer-dependent

Journal of High Energy Physics
In quantum gravity, it has been argued that a proper accounting of the role played by an observer promotes the von Neumann algebra of observables in a given spacetime subregion from Type III to Type II.
Julian De Vuyst, Stefan Eccles, Philipp A. Höhn, Josh Kirklin   +3 more
doaj   +1 more source

ENTROPY OF GRAVITATIONAL WAVES

Reports
Gravitational waves (GWs), the propagating perturbations within the structure of spacetime, provide a unique window into the dynamics of massive celestial objects and their cataclysmic events such as binary black hole (BBH), black hole – neutron star, binary neutron star (BNS) merger.
Nurzhan Ussipov, Almat Akhmetali, Marat Zaidyn, Aigerim Akniyazova, Aknur Sakan, Gulnur Subebekova   +5 more
openaire   +1 more source

Time evolution of entropy in gravitational collapse [PDF]

Journal of Cosmology and Astroparticle Physics, 2009
9 pages, 6 ...
openaire   +2 more sources

Gravitational entropy and thermodynamics away from the horizon [PDF]

We define, by an integral of geometric quantities over a spherical shell of arbitrary radius, an invariant gravitational entropy. This definition relies on defining a gravitational energy and pressure, and it reduces at the horizon of both black branes ...
Brustein, R, Medved, A J M
core   +2 more sources

Hot and Heavy Matters in the Foundations of Statistical Mechanics [PDF]

, 2010
Are the generalizations of classical equilibrium thermodynamics true of self-gravitating systems? This question has not been addressed from a foundational perspective, but here I tackle it through a study of the "paradoxes" commonly said to afflict such ...
Craig Callender, Callender, Craig
core   +1 more source

Gravitational entropy and the flatness, homogeneity and isotropy puzzles

Physics Letters B
We suggest a new explanation for the observed large scale flatness, homogeneity and isotropy of the universe. The basic ingredients are Einstein's theory of gravity and Hawking's method of computing the gravitational entropy. The new twist is provided by
Neil Turok, Latham Boyle
doaj   +1 more source

Replica wormholes and the entropy of Hawking radiation

Journal of High Energy Physics, 2020
The information paradox can be realized in anti-de Sitter spacetime joined to a Minkowski region. In this setting, we show that the large discrepancy between the von Neumann entropy as calculated by Hawking and the requirements of unitarity is fixed by ...
Ahmed Almheiri, Thomas Hartman, Juan Maldacena, Edgar Shaghoulian, Amirhossein Tajdini   +4 more
doaj   +1 more source