Laboratory simulation of Euclid-like sky images to study the impact of CCD radiation damage on weak gravitational lensing

2014 ◽  
Author(s):  
T. Prod'homme ◽  
P. Verhoeve ◽  
T. Oosterbroek ◽  
N. Boudin ◽  
A. Short ◽  
...  
Keyword(s):  
Radiation Damage ◽  
Gravitational Lensing ◽  
Laboratory Simulation ◽  
Weak Gravitational Lensing ◽  
The Impact

scholarly journals Scale dependence of galaxy biasing investigated by weak gravitational lensing: An assessment using semi-analytic galaxies and simulated lensing data

2018 ◽  
Vol 613 ◽  
pp. A15 ◽  
Author(s):  
Patrick Simon ◽  
Stefan Hilbert
Keyword(s):  
Gravitational Lensing ◽  
Spatial Scales ◽  
Scale Dependence ◽  
Reconstruction Technique ◽  
Weak Gravitational Lensing ◽  
Physical Scale ◽  
The Galaxy ◽  
Galaxy Bias ◽  
The Impact ◽  
Lens Galaxies

Galaxies are biased tracers of the matter density on cosmological scales. For future tests of galaxy models, we refine and assess a method to measure galaxy biasing as a function of physical scalekwith weak gravitational lensing. This method enables us to reconstruct the galaxy bias factorb(k) as well as the galaxy-matter correlationr(k) on spatial scales between 0.01hMpc−1≲k≲ 10hMpc−1for redshift-binned lens galaxies below redshiftz≲ 0.6. In the refinement, we account for an intrinsic alignment of source ellipticities, and we correct for the magnification bias of the lens galaxies, relevant for the galaxy-galaxy lensing signal, to improve the accuracy of the reconstructedr(k). For simulated data, the reconstructions achieve an accuracy of 3–7% (68% confidence level) over the abovek-range for a survey area and a typical depth of contemporary ground-based surveys. Realistically the accuracy is, however, probably reduced to about 10–15%, mainly by systematic uncertainties in the assumed intrinsic source alignment, the fiducial cosmology, and the redshift distributions of lens and source galaxies (in that order). Furthermore, our reconstruction technique employs physical templates forb(k) andr(k) that elucidate the impact of central galaxies and the halo-occupation statistics of satellite galaxies on the scale-dependence of galaxy bias, which we discuss in the paper. In a first demonstration, we apply this method to previous measurements in the Garching-Bonn Deep Survey and give a physical interpretation of the lens population.

scholarly journals Weak Gravitational Lensing by Horndeski Theory Using the Gauss-Bonnet Theorem

2020 ◽  
Author(s):  
Wajiha Javed ◽  
Jameela Abbas ◽  
Yashmitha Kumaran ◽  
Ali Övgün
Keyword(s):  
Black Hole ◽  
Gravitational Lensing ◽  
Deflection Angle ◽  
Field Approximation ◽  
Weak Field ◽  
Plasma Medium ◽  
Weak Gravitational Lensing ◽  
The Deflection Angle ◽  
Bonnet Theorem ◽  
The Impact

The main goal of this paper is to study the weak gravitational lensing by Horndeski black hole in weak field approximation. In order to do so, we exploit the Gibbons-Werner method to the optical geometry of Horndeski black hole and implement the Gauss-Bonnet theorem to accomplish the deflection angle of light in weak field region. Furthermore, we have endeavored to extend the scale of our work by comprising the impact of plasma medium on the deflection angle as properly. Later, the graphical influence of the deflection angle of photon on Horndeski black hole in plasma and non-plasma medium is examined.

scholarly journals Effect of the Hair on Deflection Angle by Asymptotically Flat Black Holes in Einstein-Maxwell-Dilaton Theory

2019 ◽  
Author(s):  
Wajiha Javed ◽  
Jameela Abbas ◽  
Ali Övgün
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Gravitational Lensing ◽  
Deflection Angle ◽  
Maxwell Theory ◽  
Weak Gravitational Lensing ◽  
Asymptotically Flat ◽  
The Deflection Angle ◽  
The Impact ◽  
Hairy Black Hole

In this paper, we are interested in a model of exact asymptotically flat charged hairy black holes in the background of dilaton potential. We study the weak gravitational lensing in the spacetime of hairy black hole in Einstein-Maxwell theory with a non-minimally coupled dilaton and its non-trivial potential. In doing so, we use the optical geometry of the flat charged hairy black hole for some range of parameter $\gamma$. For this purpose, by using Gauss-Bonnet theorem, we obtain the deflection angle of photon in a spherically symmetric and asymptotically flat spacetime. Moreover, we also investigate the impact of plasma medium on weak gravitational lensing by asymptotically flat charged hairy black hole with a  dilaton potential. Our analytically analyses show the effect of the hair on the deflection angle in weak field limits.

scholarly journals Simultaneous modelling of matter power spectrum and bispectrum in the presence of baryons

2021 ◽  
Author(s):  
Giovanni Aricó ◽  
Raul E Angulo ◽  
Carlos Hernández-Monteagudo ◽  
Sergio Contreras ◽  
Matteo Zennaro
Keyword(s):  
Power Spectrum ◽  
Gravitational Lensing ◽  
Weak Gravitational Lensing ◽  
Matter Power Spectrum ◽  
Hydrodynamical Simulations ◽  
The Impact

Abstract We demonstrate that baryonification algorithms, which displace particles in gravity-only simulations according to physically-motivated prescriptions, can simultaneously capture the impact of baryonic physics on the 2 and 3-point statistics of matter. Specifically, we show that our implementation of a baryonification algorithm jointly fits the changes induced by baryons on the power spectrum and equilateral bispectrum on scales up to k = 5h Mpc−1 and redshifts 0 ≤ z ≤ 2, as measured in six different cosmological hydrodynamical simulations. The accuracy of our fits is typically $\sim 1\%$ for the power spectrum, and for the equilateral and squeezed bispectra, which somewhat degrades to $\sim 3\%$ for simulations with extreme feedback prescriptions. Our results support the physical assumptions underlying baryonification approaches and encourage their use in interpreting weak gravitational lensing and other cosmological observables.

scholarly journals KiDS+VIKING-450 and DES-Y1 combined: Cosmology with cosmic shear

2020 ◽  
Vol 638 ◽  
pp. L1 ◽  
Author(s):  
S. Joudaki ◽  
H. Hildebrandt ◽  
D. Traykova ◽  
N. E. Chisari ◽  
C. Heymans ◽  
...  
Keyword(s):  
Dark Energy ◽  
Cosmic Microwave Background ◽  
Gravitational Lensing ◽  
Error Model ◽  
Calibration Error ◽  
Microwave Background ◽  
Weak Gravitational Lensing ◽  
Dark Energy Survey ◽  
Cosmic Shear ◽  
Energy Survey

We present a combined tomographic weak gravitational lensing analysis of the Kilo Degree Survey (KV450) and the Dark Energy Survey (DES-Y1). We homogenize the analysis of these two public cosmic shear datasets by adopting consistent priors and modeling of nonlinear scales, and determine new redshift distributions for DES-Y1 based on deep public spectroscopic surveys. Adopting these revised redshifts results in a 0.8σ reduction in the DES-inferred value for S​8, which decreases to a 0.5σ reduction when including a systematic redshift calibration error model from mock DES data based on the MICE2 simulation. The combined KV450+DES-Y1 constraint on S8 = 0.762−0.024+0.025 is in tension with the Planck 2018 constraint from the cosmic microwave background at the level of 2.5σ. This result highlights the importance of developing methods to provide accurate redshift calibration for current and future weak-lensing surveys.

scholarly journals KiDS-450: cosmological parameter constraints from tomographic weak gravitational lensing

2016 ◽  
Vol 465 (2) ◽  
pp. 1454-1498 ◽  
Author(s):  
H. Hildebrandt ◽  
M. Viola ◽  
C. Heymans ◽  
S. Joudaki ◽  
K. Kuijken ◽  
...  
Keyword(s):  
Gravitational Lensing ◽  
Cosmological Parameter ◽  
Weak Gravitational Lensing ◽  
Parameter Constraints

Current status of weak gravitational lensing

2002 ◽  
Vol 46 (12) ◽  
pp. 767-781 ◽  
Author(s):  
Henk Hoekstra ◽  
H.K.C Yee ◽  
Michael D Gladders
Keyword(s):  
Gravitational Lensing ◽  
Current Status ◽  
Weak Gravitational Lensing

scholarly journals CFHTLenS: the relation between galaxy dark matter haloes and baryons from weak gravitational lensing

2013 ◽  
Vol 437 (3) ◽  
pp. 2111-2136 ◽  
Author(s):  
Malin Velander ◽  
Edo van Uitert ◽  
Henk Hoekstra ◽  
Jean Coupon ◽  
Thomas Erben ◽  
...  
Keyword(s):  
Dark Matter ◽  
Gravitational Lensing ◽  
Weak Gravitational Lensing

scholarly journals Perturbative deflection angle, gravitational lensing in the strong field limit and the black hole shadow

2021 ◽  
Vol 81 (3) ◽  
Author(s):  
Junji Jia ◽  
Ke Huang
Keyword(s):  
Gravitational Lensing ◽  
Deflection Angle ◽  
Strong Field ◽  
Distance Effect ◽  
Critical Value ◽  
Field Limit ◽  
Perturbative Method ◽  
The Deflection Angle ◽  
The Impact ◽  
Strong Field Limit

AbstractA perturbative method to compute the deflection angle of both timelike and null rays in arbitrary static and spherically symmetric spacetimes in the strong field limit is proposed. The result takes a quasi-series form of $$(1-b_c/b)$$ ( 1 - b c / b ) where b is the impact parameter and $$b_c$$ b c is its critical value, with coefficients of the series explicitly given. This result also naturally takes into account the finite distance effect of both the source and detector, and allows to solve the apparent angles of the relativistic images in a more precise way. From this, the BH angular shadow size is expressed as a simple formula containing metric functions and particle/photon sphere radius. The magnification of the relativistic images were shown to diverge at different values of the source-detector angular coordinate difference, depending on the relation between the source and detector distance from the lens. To verify all these results, we then applied them to the Hayward BH spacetime, concentrating on the effects of its charge parameter l and the asymptotic velocity v of the signal. The BH shadow size were found to decrease slightly as l increases to its critical value, and increase as v decreases from light speed. For the deflection angle and the magnification of the images however, both the increase of l and decrease of v will increase their values.

Weak Gravitational Lensing by a Sample of X‐Ray–luminous Clusters of Galaxies. II. Comparison with Virial Masses

2002 ◽  
Vol 579 (1) ◽  
pp. 227-235 ◽  
Author(s):  
Ragnvald J. Irgens ◽  
Per B. Lilje ◽  
Hakon Dahle ◽  
S. J. Maddox
Keyword(s):  
Gravitational Lensing ◽  
Clusters Of Galaxies ◽  
Weak Gravitational Lensing ◽  
X Ray
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