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A method of general applicability has been developed, whereby the null geodesic equations of the Einstein-Straus-de Sitter metric can be integrated simultaneously in terms of the curvature constant $k$. The purpose is to generalize the…

General Relativity and Quantum Cosmology · Physics 2024-09-06 Mourad Guenouche

Infrared images of the Q 0957+561 gravitational lens obtained with the Hubble Space Telescope show two large (\sim 5 arcsec) lensed images of the z_s=1.41 quasar host galaxy. Parts of the host galaxy are doubly-imaged like the quasar, while…

The solution proposed by Zhao & Qin to the apparent conflict between gravitational lens time delays, local estimates of the Hubble constant and current expectations for the structure of CDM halos is discussed. Two essential points emerge.…

Astrophysics · Physics 2007-05-23 C. S. Kochanek

We present a new determination of the time delay of the gravitational lens system HE1104-1805 ('Double Hamburger') based on a previously unpublished dataset. We argue that the previously published value of dt_(A-B)=0.73 years was affected…

Astrophysics · Physics 2009-11-07 R. Gil-Merino , L. Wisotzki , J. Wambsganss

The local expansion rate of the Universe is parametrized by the Hubble constant, $H_0$, the ratio between recession velocity and distance. Different techniques lead to inconsistent estimates of $H_0$. Observations of Type Ia supernovae…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-17 Inh Jee , Sherry Suyu , Eiichiro Komatsu , Christopher D. Fassnacht , Stefan Hilbert , Léon V. E. Koopmans

We analyze the measurement of cosmological distances in the presence of torsion in both Einstein-Cartan and Poincare gauge theory of gravity. Using the modified cosmological distance measurements, we use the observed time delays in…

General Relativity and Quantum Cosmology · Physics 2023-09-15 Siamak Akhshabi , Saboura Zamani

We investigate the possibility of measuring the Hubble constant, the fractional energy density components and the equation of state parameter of the ``dark energy'' using lensed multiple images of high-redshift supernovae. With future…

Astrophysics · Physics 2009-11-07 A. Goobar , E. Mortsell , R. Amanullah , P. Nugent

The use of time-delay gravitational lenses to examine the cosmological expansion introduces a new standard ruler with which to test theoretical models. The sample suitable for this kind of work now includes 12 lens systems, which have thus…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Jun-Jie Wei , Xue-Feng Wu , Fulvio Melia

One challenge in strong gravitational lensing cosmography is the measurement of time delays between multiple lensed images, which are essential for constraining the Hubble constant (\(H_0\)). In this study, we investigate how assumptions…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-20 Guanhua Rui , Bin Hu , Wei Du

The Hubble Tension is a well-known issue in modern cosmology that refers to the apparent disagreement in inferences of the Hubble constant $H_0$ as found through low-redshift observations and those derived from the $\Lambda$CDM model…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-22 Joshua Ange , Joel Meyers

We use the local value of the Hubble constant recently measured with 2.4% precision, as well as the latest compilation of cosmic chronometers data, together with standard probes such as Supernovae Type Ia and Baryon Acoustic Oscillation…

General Relativity and Quantum Cosmology · Physics 2016-08-10 Rafael C. Nunes , Supriya Pan , Emmanuel N. Saridakis

Multiply-imaged supernovae (SNe) provide a novel means of constraining the Hubble constant ($H_0$). Such measurements require a combination of precise models of the lensing mass distribution and an accurate estimate of the relative time…

We present constraints on the cosmological constant lambda_0 and the density parameter Omega_0 from joint constraints from the analyses of gravitational lensing statistics of the Jodrell Bank-VLA Astrometric Survey (JVAS), optical…

Astrophysics · Physics 2007-05-23 J. F. Macias-Perez , P. Helbig , R. Quast , A. Wilkinson , R. D. Davies

A particular open problem in cosmology is whether dark matter on small scales is clumpy, forming gravitationally-bound halos distributed within the Galaxy. The practical difficulties inherent in testing this hypothesis stem from the fact…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-13 Francesca von Braun-Bates

The open problems related to cosmological tensions in current times have opened new paths to study new probes to constrain cosmological parameters in standard and extended cosmologies, in particular, to determine at a local level the value…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-22 Rodrigo Sandoval-Orozco , Celia Escamilla-Rivera , Rebecca Briffa , Jackson Levi Said

We show that a cosmic standard ruler can be constructed from the joint measurement of the time delay (dt) between gravitationally lensed quasar images and the velocity dispersion (sigma^2) of the lensing galaxy. This is specifically shown,…

Cosmology and Nongalactic Astrophysics · Physics 2009-12-06 Danuta Paraficz , Jens Hjorth

Using Fermat's principle, we analyze the effects of very long wavelength gravitational waves upon the images of a gravitationally lensed quasar. We show that the lens equation in the presence of gravity waves is equivalent to that of a lens…

Astrophysics · Physics 2011-09-09 J. Frieman , D. Harari , G. Surpi

f(R) gravity is thought to be an alternative to dark energy which can explain the acceleration of the universe. It has been tested by different observations including type Ia supernovae (SNIa), the cosmic microwave background (CMB), the…

Cosmology and Nongalactic Astrophysics · Physics 2012-07-12 Kai Liao , Zong-Hong Zhu

Gravitational lensing time-delays using standard candles can provide tremendous leverage to cosmology. A recently discovered gravitationally lensed type Ia supernova, iPTF16geu, may yield a precise and accurate measurement of the Hubble…

Astrophysics of Galaxies · Physics 2017-11-15 Chien-Hsiu Lee

Hubble Space Telescope observations from December 11 2015 detected the expected fifth counter image of SN Refsdal at $z = 1.49$. In this letter, we compare the time delay predictions from numerous models with the measured value derived by…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-21 J. Vega-Ferrero , J. M. Diego , V. Miranda , G. M. Bernstein
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