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pro vyhledávání: '"Faraoni P"'
The Tolman-Ehrenfest criterion of thermal equilibrium for a static fluid in a static spacetime is generalized to stationary heat conduction, in the approximation in which backreaction is negligible. Applying this generalized criterion to the Hawking
Externí odkaz:
http://arxiv.org/abs/2409.12861
The ultralocal limit along timelike geodesics, in which any geometry reduces to Bianchi I, does not extend to non-geodesic timelike observers. Exceptions are discussed, including particles with variable mass, test particles in Einstein frame scalar-t
Externí odkaz:
http://arxiv.org/abs/2408.00871
It is shown that an exactly static and spherically symmetric black hole event horizon cannot be embedded in a time-dependent geometry. Forcing it to do so results in a naked null singularity at the would-be horizon. Therefore, since the universe is e
Externí odkaz:
http://arxiv.org/abs/2407.14549
Autor:
Karolinski, Numa, Faraoni, Valerio
The Tolman-Ehrenfest criterion for the thermal equilibrium of a fluid at rest in a static general-relativistic geometry is generalized to scalar-tensor gravity. The gravitational scalar field, which fixes the strength of the effective gravitational c
Externí odkaz:
http://arxiv.org/abs/2406.09251
Autor:
Houle, Julien, Faraoni, Valerio
The phase space of Bianchi I universes in vacuum Brans-Dicke gravity is analyzed in terms of physical variables. The behaviour of the solutions of the field equations near the fixed points (which are solutions of Einstein gravity) is compared with ba
Externí odkaz:
http://arxiv.org/abs/2404.19470
Autor:
Karolinski, Numa, Faraoni, Valerio
We test ideas of the recently proposed first-order thermodynamics of scalar-tensor gravity using an exact geometry sourced by a conformally coupled scalar field. We report a non-monotonic behaviour of the effective ``temperature of gravity'' not obse
Externí odkaz:
http://arxiv.org/abs/2401.04877
Autor:
Faraoni, Valerio, Zeyn, Carla
Disformal transformations of Friedmann-Lema\^itre-Robertson-Walker and Bianchi geometries are analyzed in the context of scalar-tensor gravity. Novel aspects discussed explicitly are the $3+1$ splitting, the effective fluid equivalent of the gravitat
Externí odkaz:
http://arxiv.org/abs/2401.00091
The ``ugly duckling'' of the Segr\'e-Pleba\'nski-Hawking-Ellis classification of stress-energy tensors is believed to be either impossible or extremely difficult to realise in Einstein gravity. Effective stress-energy tensors in alternative gravity o
Externí odkaz:
http://arxiv.org/abs/2307.13846
The Bekenstein-Hawking entropy of a black hole is proportional to its horizon area, hence in $D=2$ spacetime dimensions it is constant because the horizon degenerates into two points. This fact is consistent with Einstein's gravity becoming topologic
Externí odkaz:
http://arxiv.org/abs/2303.02663
Autor:
Samantha Gilg, Sebastian Acosta, Rohit S. Loomba, Claire Rizk, Gary E. Stapleton, David Faraoni, Fabio Savorgnan
Publikováno v:
Pediatric Investigation, Vol 8, Iss 2, Pp 135-138 (2024)
Externí odkaz:
https://doaj.org/article/f604f71e8f1043a6a3ae9d3c80be75c2
