Results 21 to 30 of about 51,813 (205)
Einstein and Rastall theories of gravitation in comparison
European Physical Journal C: Particles and Fields, 2018 We profit by a recent paper of Visser claiming that Rastall gravity is equivalent to Einstein gravity to compare the two gravitational theories in a general way. Our conclusions are different from Visser’s ones.
F. Darabi +4 more
doaj +1 more source
$$f(\mathcal {G})$$ f(G) Noether cosmology
European Physical Journal C: Particles and Fields, 2020 We develop the n-dimensional cosmology for $$f(\mathcal {G})$$ f(G) gravity, where $$\mathcal {G}$$ G is the Gauss–Bonnet topological invariant. Specifically, by the so-called Noether Symmetry Approach, we select $$f(\mathcal {G})\simeq \mathcal {G}^k ...
Francesco Bajardi, Salvatore Capozziello
doaj +1 more source
DeWitt boundary condition is consistent in Hořava-Lifshitz quantum gravity
Physics Letters B, 2022 In quantum cosmology the DeWitt boundary condition is a proposal to set the wave function of the universe to vanish at the classical big-bang singularity.
Hiroki Matsui +2 more
doaj +1 more source
Braneworlds and Quantum States of Relativistic Shells [PDF]
, 2007 We review some applications of relativistic shells that are relevant in the context of quantum gravity/quantum cosmology. Using a recently developed approach, the stationary states of this general relativistic system can be determined in the ...
Ansoldi, Stefano
core +2 more sources
Black Hole Thermodynamics [PDF]
, 2014 The discovery in the early 1970s that black holes radiate as black bodies has radically affected our understanding of general relativity, and offered us some early hints about the nature of quantum gravity.
Carlip, S.
core +1 more source
Journal of High Energy Physics, 2020 It was recently shown that the homogeneous and isotropic cosmology of a massless scalar field coupled to general relativity exhibits a new hidden conformal invariance under Mobius transformation of the proper time, additionally to the invariance under ...
Jibril Ben Achour, Etera R. Livine
doaj +1 more source
Minisuperspace Quantum Cosmology in Metric and Affine Theories of Gravity
Universe, 2022 Minisuperspace Quantum Cosmology is an approach by which it is possible to infer initial conditions for dynamical systems which can suitably represent observable and non-observable universes. Here we discuss theories of gravity which, from various points
Salvatore Capozziello, Francesco Bajardi
doaj +1 more source
Two-photon amplitude interferometry for precision astrometry
The Open Journal of Astrophysics, 2022 Improved quantum sensing of photons from astronomical objects could provide high resolution observations in the optical benefiting numerous fields, including general relativity, dark matter studies, and cosmology.
Paul Stankus +3 more
doaj +1 more source
, 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
Vanishing Cosmological Constant in Modified Gauss-Bonnet Gravity with Conformal Anomaly [PDF]
, 2006 We consider dark energy cosmology in a de Sitter universe filled with quantum conformal matter. Our model represents a Gauss-Bonnet model of gravity with contributions from quantum effects. To the General Relativity action an arbitrary function of the GB
Bergshoeff E. A. +18 more
core +3 more sources