Wormholes in viable $$f(R)$$ f ( R ) modified theories of gravity and weak energy condition
نویسندگان
چکیده
منابع مشابه
Structure formation and generalized second law of thermodynamics in some viable f(R)-gravity models
We investigate the growth of matter density perturbations as well as the generalized second law (GSL) of thermodynamics in the framework of f(R)-gravity. We consider a spatially flat FRW universe filled with the pressureless matter and radiation which is enclosed by the dynamical apparent horizon with the Hawking temperature. For some viable f(R) models containing the Starobinsky, Hu-Sawicki, Exp...
متن کاملf(R) theories of gravity
Modified gravity theories have received increased attention lately due to combined motivation coming from high-energy physics, cosmology and astrophysics. Among numerous alternatives to Einstein’s theory of gravity, theories which include higher order curvature invariants, and specifically the particular class of f(R) theories, have a long history. In the last five years there has been a new st...
متن کامل3D weak lensing: Modified theories of gravity
Weak lensing (WL) promises to be a particularly sensitive probe of both the growth of large-scale structure as well as the fundamental relation between matter density perturbations and metric perturbations, thus providing a powerful tool with which we may constrain modified theories of gravity (MG) on cosmological scales. Future deep, wide-field WL surveys will provide an unprecedented opportun...
متن کاملMetric-affine f(R) theories of gravity
General Relativity assumes that spacetime is fully described by the metric alone. An alternative is the so called Palatini formalism where the metric and the connections are taken as independent quantities. The metric-affine theory of gravity has attracted considerable attention recently, since it was shown that within this framework some cosmological models, based on some generalized gravitati...
متن کاملStrong energy condition in R+R2 gravity.
In this paper, we study Raychaudhuri's equation in the background of R + βR 2 gravity with a phenomenological matter (ρ ∝ a(t) −n). We conclude that even though the Strong Energy Condition (S.E.C.) for Einstein's gravity, which guarantees singularity, is n ≥ 2 for ρ ∝ a(t) −n , a perturbative analysis of Raychaudhuri's equation in the background of R+βR 2 gravity reveals that the big bang singu...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: The European Physical Journal C
سال: 2015
ISSN: 1434-6044,1434-6052
DOI: 10.1140/epjc/s10052-015-3331-y