Related papers: Solar-system experimental constraints on nonlocal …
In this research paper, we explore a well-motivated parametrization of the time-dependent deceleration parameter, characterized by a cubic form, within the context of late time cosmic acceleration. The current analysis is based on the…
We use the cosmic shear data from the Canada-France-Hawaii Telescope Lensing Survey to place constraints on $f(R)$ and {\it Generalized Dilaton} models of modified gravity. This is highly complimentary to other probes since the constraints…
Modifications to the classic time-delay effect and Doppler shift in General Relativity (GR) are studied in the context of the Lorentz-violating Standard-Model Extension (SME). We derive the leading Lorentz-violating corrections to the…
Inferring spatial curvature of the Universe with high-fidelity is a longstanding interest in cosmology. However, the strong degeneracy between dark energy equation-of-state parameter $w$ and curvature density parameter $\Omega_{\rm K}$ has…
In this paper, we examine a static gravitational field with axial symmetry over probe particles in the solar system. Using the Weyl conformastatic solution as a model, we find a non-standard expression to perihelion advance due to the…
We study the constraint on $f(R)$ gravity that can be obtained by photometric primary probes of the Euclid mission. Our focus is the dependence of the constraint on the theoretical modelling of the nonlinear matter power spectrum. In the…
We study the observational constraints on the exponential gravity model of f(R)=-beta*Rs(1-e^(-R/Rs)). We use the latest observational data including Supernova Cosmology Project (SCP) Union2 compilation, Two-Degree Field Galaxy Redshift…
We discuss the classical tests of general relativity in the presence of Rindler acceleration. Among these tests the perihelion shifts give the tightest constraints and indicate that the Pioneer anomaly cannot be caused by a universal solar…
We advocate the study of supergravity models as well motivated few-parameter low-energy supersymmetric models. In this context we survey a broad range of phenomenological constraints and future tests, including present and near-future…
We perform a detailed study of the constraints from $b\to s\gamma$ on a large class of supergravity models, including generic four-parameter supergravity models, the minimal $SU(5)$ supergravity model, and $SU(5)\times U(1)$ supergravity.…
The post Newtonian parameter is considered in the Chameleon-Brans-Dicke frame. In the first step, the general form of this parameter and also effective gravitational constant is obtained. An arbitrary function for $f(\Phi)$, which indicates…
Black hole shadow images are primarily determined by the properties of photon spheres and can exhibit degeneracies across different spherically symmetric spacetime geometries. We show that time delay observables associated with higher-order…
We consider a class of well motivated string-inspired flipped $SU(5)$ supergravity models which include four supersymmetry breaking scenarios: no-scale, strict no-scale, dilaton, and special dilaton, such that only three parameters are…
To find more deliberate f(R,T) cosmological solutions, we proceed our previous paper further by studying some new aspects of the considered models via investigation of some new cosmological parameters/quantities to attain the most…
Starting from a static spherically symmetric solution of the Einstein's field equations in the second approximation in the perfect fluid scheme, in the exterior of the source, the corresponding metrics depend on a dimensionless parameter…
The Beyond Horndeski class of alternative gravity theories allow for Self-accelerating de-Sitter cosmologies with no need for a cosmological constant. This makes them viable alternatives to $\Lambda$CDM and so testing their small-scale…
We investigate the linearized form of metric f(R)-gravity, assuming that f(R) is analytic about R = 0 so it may be expanded as f(R) = R + a_2 R^2/2 + ... . Gravitational radiation is modified, admitting an extra mode of oscillation, that of…
The problem of determining the post-Newtonian parameter $\gamma$ in massive scalar-tensor theories is considered. We demonstrate equivalent correspondence between the post-Newtonian parameter $\gamma$ and the parameter appearing in the…
Solar system observations have traditionally allowed for very stringent tests of Einstein's theory of general relativity. We here revisit the possibility of using these observations to constrain gravitational parity violation as…
Non-local theories of gravity are considered extended theories of gravity, meaning that when the non-local terms are canceled out, the limit of General Relativity (GR) is obtained. Several reasons have led us to consider this theory with…