Results 71 to 80 of about 540,486 (189)
Physics Letters B, 2022 We consider Non-local Gravity in view to obtain stable and traversable wormhole solutions. In particular, the class of Non-local Integral Kernel Theories of Gravity, with the inverse d'Alembert operator in the gravitational action, is taken into account.
Salvatore Capozziello, Nisha Godani
doaj +1 more source
Modified f(R) gravity consistent with realistic cosmology: from matter dominated epoch to dark energy universe [PDF]
, 2006 We develop the general scheme for modified $f(R)$ gravity reconstruction from any realistic FRW cosmology. We formulate several versions of modified gravity compatible with Solar System tests where the following sequence of cosmological epochs occurs: a.
19386 +3 more
core +2 more sources
On Extensions of the Starobinsky Model of Inflation
Physical Sciences Forum, 2023 We propose inflationary models that are one-parametric generalizations of the Starobinsky R+R2 model. Using the conformal transformation, we obtain scalar field potentials in the Einstein frame that are one-parametric generalizations of the potential for
Vsevolod Ivanov +3 more
doaj +1 more source
Toward the Alleviation of the H0 Tension in Myrzakulov f(R,T) Gravity
UniverseIn this work, we provide a promising way to alleviate the Hubble tension within the framework of Myrzakulov f(R,T) gravity. The latter incorporates both curvature and torsion under a non-special connection. We consider the f(R,T)=R+αR2 class, which leads
Mashael A. Aljohani +3 more
doaj +1 more source
Schwarzschild-type black holes in Starobinsky-Bel-Robinson gravity
Physics Letters B, 2023 We study physical properties of a Schwarzschild-type black hole in the framework of the recently proposed Starobinsky-Bel-Robinson (SBR) modified theory of gravity, working perturbatively in the coupling constant.
Ruben Campos Delgado, Sergei V. Ketov
doaj +1 more source
Lemaître-Tolman-Bondi static universe in Rastall-like gravity
Nuclear Physics B, 2020 In this work, we try to obtain a stable Lemaître-Tolman-Bondi (LTB) static universe, which is spherically symmetric and radially inhomogeneous. However, this is not an easy task, and fails in general relativity (GR) and various modified gravity theories,
Zhong-Xi Yu, Shou-Long Li, Hao Wei
doaj +1 more source
Modified Gravity Away from a $\Lambda$CDM Background
, 2019 Within the effective field theory approach to cosmic acceleration, the background expansion can be specified separately from the gravitational modifications. We explore the impact of modified gravity in a background different from a cosmological constant
Brando, Guilherme +3 more
core +1 more source
The gravitational-wave luminosity distance in modified gravity theories [PDF]
, 2018 In modified gravity the propagation of gravitational waves (GWs) is in general different from that in general relativity. As a result, the luminosity distance for GWs can differ from that for electromagnetic signals, and is affected both by the dark ...
Belgacem, Enis +3 more
core +3 more sources
Observational tests of modified gravity
Physical Review D, 2008 Modified gravity theories have richer observational consequences for large-scale structure than conventional dark energy models, in that different observables are not described by a single growth factor even in the linear regime. We examine the relationships between perturbations in the metric potentials, density and velocity fields, and discuss ...
Jain, Bhuvnesh, Zhang, Pengjie
openaire +4 more sources
Dark Energy vs. Modified Gravity
, 2016 Understanding the reason for the observed accelerated expansion of the Universe represents one of the fundamental open questions in physics. In cosmology, a classification has emerged among physical models for the acceleration, distinguishing between ...
Joyce, Austin +2 more
core +1 more source