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Related papers: Is There A Cosmological Constant?

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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…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Benjamin M. Dobke , Lindsay J. King , Christopher D. Fassnacht , Matthew W. Auger

This study explores the cosmological constant problem and modified uncertainty principle within a unified framework inspired by a void-dominated scenario. In a recent paper~\cite{Yusofi:2022hgg}, voids were modeled as spherical bubbles of…

General Relativity and Quantum Cosmology · Physics 2024-05-14 S. Ahmadi , E. Yusofi , M. A. Ramzanpour

The probability distribution of lens image separations is calculated for the ``standard'' gravitational lensing statistics model in an arbitrary, flat Robertson-Walker universe, where lensing galaxies are singular isothermal spheres that…

Astrophysics · Physics 2008-11-26 Myeong-Gu Park

In this paper, time variable cosmological constant, dubbed {\it age cosmological constant}, is investigated motivated by the fact: any cosmological length scale and time scale can introduce a cosmological constant or vacuum energy density…

Cosmology and Nongalactic Astrophysics · Physics 2010-06-28 Lixin Xu , Jianbo Lu , Wenbo Li

Increasing improvements in the independent determinations of the Hubble constant and the age of the universe now seem to indicate that we need a small non-vanishing cosmological constant to make the two independent observations consistent…

High Energy Physics - Phenomenology · Physics 2009-10-28 Anupam Singh

Strong gravitational lenses with measured time delays between the multiple images and models of the lens mass distribution allow a one-step determination of the time-delay distance, and thus a measure of cosmological parameters. We present…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 S. H. Suyu , M. W. Auger , S. Hilbert , P. J. Marshall , M. Tewes , T. Treu , C. D. Fassnacht , L. V. E. Koopmans , D. Sluse , R. D. Blandford , F. Courbin , G. Meylan

There is a discussion of the temperature anisotropy of the cosmic background radiation and of how the first Doppler peak depends on the different contributions to the vacuum energy density. An analytic calculation agrees well with numerical…

Astrophysics · Physics 2007-05-23 P. H. Frampton

The 0th, 1st and 2nd derivatives of a ``Fermat potential'' give the three D's of gravitational lensing: delay, deflection and distortion. Observations of these delays, deflections and distortions for doubly and quadruply imaged quasars give…

Astrophysics · Physics 2007-05-23 Paul L. Schechter

We consider a dynamical approach to the cosmological constant. There is a scalar field with a potential whose minimum occurs at a generic, but negative, value for the vacuum energy, and it has a non-standard kinetic term whose coefficient…

High Energy Physics - Theory · Physics 2016-09-06 Shinji Mukohyama , Lisa Randall

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…

Astrophysics · Physics 2009-11-07 HongSheng Zhao , Bo Qin

We propose cosmological redshift-space distortion of correlation functions of galaxies and quasars as a probe of both the density parameter $\Omega_0$ and the cosmological constant $\lambda_0$. In particular, we show that redshift-space…

Astrophysics · Physics 2009-10-28 Takahiko Matsubara , Yasushi Suto

In this paper we suppose that the cosmological constant will change when the universe expends. For a general consideration, the cosmological constant is assumed to be a function of scale factor and Hubble constant. According to the ADM…

Cosmology and Nongalactic Astrophysics · Physics 2010-08-03 Jin-Zhang Tang , Qiang Xu

The potential of gravitational lenses for providing direct, physical measurements of the Hubble constant, free from systematic errors associated with the traditional distance ladder, has long been recognized. However, it is only recently…

Astrophysics · Physics 2007-05-23 Roger D. Blandford , Tomislav Kundic

We use observations from the CASTLES survey of gravitational lenses to study extinction in 23 lens galaxies with $0 < z_l < 1$. The median differential extinction between lensed images is $\Delta E(\bv) = 0.05$ mag, and the directly…

A diverse set of observations now compellingly suggest that Universe possesses a nonzero cosmological constant. In the context of quantum-field theory a cosmological constant corresponds to the energy density of the vacuum, and the wanted…

Astrophysics · Physics 2014-10-13 Lawrence M. Krauss , Michael S. Turner

Cosmological bounds on neutrinos and additional hypothetical light thermal relics, such as QCD axions, are currently among the most restrictive ones. These limits mainly rely on Cosmic Microwave Background temperature anisotropies.…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-30 William Giarè , Olga Mena , Eleonora Di Valentino

We combine photometry and lens modeling to study the properties of 17 gravitational lens galaxies between z=0.1 and 1. Most of the lens galaxies are passively evolving early-type galaxies, with a few spirals. The colors, scale lengths, and…

Astrophysics · Physics 2010-03-01 C. R. Keeton , C. S. Kochanek , E. E. Falco

I discuss the Hubble parameter $H_0$, the age of the universe $t_0$, the density $\Omega_0$, and the cosmological constant $\Lambda$. To focus the discussion, I concentrate on the issue of the value of the density $\Omega_0$ in currently…

Astrophysics · Physics 2016-08-30 Joel R. Primack

Recently, some divergent conclusions about cosmic acceleration were obtained using type Ia supernovae (SNe Ia), with opposite assumptions on the intrinsic luminosity evolution. In this paper, we use strong gravitational lensing systems to…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-20 Z. L. Tu , J. Hu , F. Y. Wang
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