Related papers: Higher Dimensional Cosmological Implications Of A …
In this paper, we investigate the effects of non-commutative phase-space on the quintom cosmological model. In that case, we discuss $\Lambda_{1}$, $\Lambda_{2}$ and other cosmological parameters and show that they are associated to…
We discuss the classical cosmological tests for a large class of FRW type models driven by a decaying vacuum energy density. Analytic expressions for the lookback time, age of the universe, luminosity distance, angular diameter, and galaxy…
We study constraints that anticipated DEEP survey galaxy counts versus redshift data will place on cosmological model parameters in models with and without a constant or time-variable cosmological constant $\Lambda$. This data will result…
We investigate the effect of a cosmological constant $\Lambda$ on the geometry generated by a two-dimensional disclination in a conformal metric framework. For $\Lambda>0$, we obtain an exact analytic solution of the Liouville-type…
We examine the constraints that satellite-acquired Type Ia and IIP supernova apparent magnitude versus redshift data will place on cosmological model parameters in models with and without a constant or time-variable cosmological constant…
We study the effect of the cosmological constant on the statistical properties of gravitational lenses in flat cosmologies (Omega_{0}+lambda_{0} = 1). It is shown that some of the lens observables are strongly affected by the cosmological…
Some cosmological consequences of first order quantum corrections to Maxwell electrodynamics are investigated in the context of a spatially flat homogeneous and isotropic universe driven by a magnetic field plus a cosmological term…
A phenomenological model is proposed to explain the recent observed cosmological variation of the fine structure constant as an effect of the quantum vacuum, assuming a flat universe with cosmological constant $\Lambda$ in the cases…
In this communication, we consider a wide class of extensions to General Relativity that break explicitly the Einstein Equivalence Principle by introducing a multiplicative coupling between a scalar field and the electromagnetic Lagrangian.…
Next year we will celebrate 100 years of the cosmological term, $\Lambda$, in Einstein's gravitational field equations, also 50 years since the cosmological constant problem was first formulated by Zeldovich, and almost about two decades of…
Dimensional reduction has proven to be a surprisingly powerful tool for delineating the boundary between the string landscape and the swampland. Bounds from the Weak Gravity Conjecture and the Repulsive Force Conjecture, for instance, are…
A broader perspective is suggested for the study of higher dimensional cosmological models. [1986: Considerations involving the Einstein constraints and the Ricci form of the evolution equations for spatially homogeneous spacetimes in 4 or…
Exact solutions of the Einstein field equations with cosmic string and space varying cosmological constant, viz., $\Lambda= \Lambda(r)$, in the energy-momentum tensors are presented. Three cases have been studied: where variable…
One application of the Cosmological Gravitational Lensing in General Relativity is the measurement of the Hubble constant H_0 using the time delay Delta t between multiple images of lensed quasars. This method has already been applied,…
A degeneracy in strong lens model is shown analytically. The observed time delays and quasar image positions might {\it not} uniquely determine the concentration and the extent of the lens galaxy halo mass distribution. Simply hardwiring…
We use supernovae measurements, calibrated by the local determination of the Hubble constant $H_0$ by SH0ES, to interpolate the distance-redshift relation using Gaussian process regression. We then predict, independent of the cosmological…
Observational constraints guide one forcefully to examine models in which the matter density is substantially less than critical density. Particularly noteworthy are those which are consistent with inflation. For these models, microwave…
Upcoming ground and space based observatories such as the DES, the LSST, the JDEM concepts and the SKA, promise to dramatically increase the size of strong gravitational lens samples. A significant fraction of the systems are expected to be…
In this year, in which we celebrate 100 years of the cosmological term, $\Lambda$, in Einstein's gravitational field equations, we are still facing the crucial question whether $\Lambda$ is truly a fundamental constant or a mildly evolving…
Motivated by the mounting evidence for dark energy, here we explore the consequences of a fundamental cosmological constant $\Lambda$ for our universe. We show that when the gravitational entropy of a pure DeSitter state ultimately wins…