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This paper and the others in the series challenge the standard model of the effects of gravitational lensing on observations at large distances. We show that due to the cumulative effect of lensing, areas corresponding to an observed solid…

General Relativity and Quantum Cosmology · Physics 2009-10-30 Nazeem Mustapha , B. A. Bassett , Charles Hellaby , G. F. R. Ellis

We discuss how inhomogeneities of the universe affect observations of the gravitational lensing; (1) the bending angle, (2) the lensing statistics and (3) the time delay. In order to take account of the inhomogeneities, the Dyer-Roeder…

Astrophysics · Physics 2009-10-30 Hideki Asada

I discuss the spherically symmetric but inhomogeneous Lemaitre-Tolman- Bondi (LTB) metric, which provides an exact toy model for an inhomogeneous universe. Since we observe light rays from the past light cone, not the expansion of the…

Astrophysics · Physics 2008-11-26 Kari Enqvist

The paper studies the correction to the distance modulus induced by inhomogeneities and averaged over all directions from a given observer. The inhomogeneities are modeled as mass-compensated voids in random or regular lattices within…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-13 Valentin Kostov

We evaluate the effect of small scale inhomogeneities on large scale observations within the statistics of gravitationally lensed quasars. At this aim, we consider a cosmological model whose large scale properties (dynamics, matter…

Astrophysics · Physics 2007-05-23 G. Covone , M. Sereno , R. de Ritis

Given the dimensions (including thickness) and rotation speeds for an axisymmetric galaxy, a closed-loop iterative method is designed to find the total mass, density, and surface-mass density (SMD)distributions. There is no need for…

Astrophysics · Physics 2016-08-30 Kenneth F. Nicholson

Observations of the CMB can be contaminated by diffuse foreground emission from sources such as Galactic dust and synchrotron radiation. In these cases, the morphology of the contaminating source is known from observations at different…

I review the characteristics of high redshift galaxies, with particular attention to the effects of dust obscuration on the observed light. Galaxies at redshift z~1 and at z>2 are discussed separately, as the accessible information for each…

Astrophysics · Physics 2007-05-23 Daniela Calzetti

We present Monte Carlo radiative transfer simulations for spiral galaxies modelled as a stellar disk and a two-phase clumpy dust distribution. We divide the volume occupied by the dust into a three-dimensional grid and assign each cell a…

Astrophysics · Physics 2009-10-31 Simone Bianchi , Andrea Ferrara , Jon Davies , Paul Alton

We model the large scale late time universe as a Lambda-CDM cosmology driven by cosmological constant and perfect dust fluid. Our aim is to find new solutions in the matter and Lambda epoch consistent with inflationary initial conditions,…

High Energy Physics - Theory · Physics 2013-05-29 Toby Wiseman , Benjamin Withers

We investigate the luminosity and redshift dependence of the quasar continuum by means of composite spectrum using a large non-BAL radio-quiet quasar sample drawn from the Sloan Digital Sky Survey. Quasar continuum slopes in the UV-Opt band…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-24 Xiaoyi Xie , Shiyin Shen , Zhengyi Shao , Jun Yin

The inhomogeneous distribution of matter in the non-linear regime of galaxies, clusters of galaxies and voids is described by an exact, spherically symmetric inhomogeneous solution of Einstein's gravitational field equations, corresponding…

Astrophysics · Physics 2009-11-11 J. W. Moffat

We present new measurements of the coherent motion of galaxies based on observations of the large-scale redshift-space distortions seen in the two-dimensional two-point correlation function of Luminous Red Galaxies in Data Release Seven of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Yong-Seon Song , Cristiano G. Sabiu , Issha Kayo , Robert C. Nichol

We derive and solve exactly the Dyer-Roeder equation in a Friedman-Robertson-Walker cosmological model with non zero cosmological constant. To take into account non homogeneous distribution of matter we use the phenomenological clumpiness…

Astrophysics · Physics 2019-06-05 M. Demianski , R. de Ritis , A. A. Marino , E. Piedipalumbo

In addition to shear and vorticity a homogeneous background may also exhibit anisotropic curvature. Here a class of spacetimes is shown to exist where the anisotropy is solely of the latter type, and the shear-free condition is supported by…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-02 Tomi S. Koivisto , David F. Mota , Miguel Quartin , Tom G. Zlosnik

Dust is a key component of galaxies, but its properties during the earliest eras of structure formation remain elusive. Here we present a simple semi-analytic model of the dust distribution in galaxies at $z \gtrsim 5$. We calibrate the…

Astrophysics of Galaxies · Physics 2025-07-08 Roy J. Zhao , Steven R. Furlanetto

Dust attenuation affects nearly all observational aspects of galaxy evolution, yet very little is known about the form of the dust-attenuation law in the distant Universe. Here, we model the spectral energy distributions (SEDs) of galaxies…

This paper investigates the phenomenon of emergence of spatial curvature. This phenomenon is absent in the Standard Cosmological Model, which has a flat and fixed spatial curvature (small perturbations are considered in the Standard…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-01 Krzysztof Bolejko

We present an analytical approximation formula for the luminosity distance in spatially flat cosmologies with dust and a cosmological constant. Apart from the overall factor, the effect of non-zero cosmological constant in our formula is…

Cosmology and Nongalactic Astrophysics · Physics 2012-02-03 Masaru Adachi , Masumi Kasai

We estimate the expected distribution of displacements between the dark matter and gas cores in simulated clusters. We use the MareNostrum Universe, one of the largest non radiative, SPH Lambda CDM cosmological simulations. We find that…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 J. E. Forero-Romero , S. Gottloeber , G. Yepes
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