scholarly journals Braneworld black hole gravitational lens: Strong field limit analysis

2005 ◽  
Vol 71 (8) ◽  
Author(s):  
Ernesto F. Eiroa
Keyword(s):  
Black Hole ◽  
Limit Analysis ◽  
Strong Field ◽  
Gravitational Lens ◽  
Field Limit ◽  
Strong Field Limit

scholarly journals Null gravitational redshift by a Reissner–Nordström black hole in the strong field limit

2020 ◽  
Vol 80 (6) ◽  
Author(s):  
Guansheng He ◽  
Chaohong Pan ◽  
Xia Zhou ◽  
Weijun Li ◽  
Lin Li
Keyword(s):  
Black Hole ◽  
Strong Field ◽  
Gravitational Redshift ◽  
Field Limit ◽  
Strong Field Limit

scholarly journals Strong Field Limit of Black Hole Gravitational Lensing

2001 ◽  
Vol 33 (9) ◽  
pp. 1535-1548 ◽  
Author(s):  
V. Bozza ◽  
S. Capozziello ◽  
G. Iovane ◽  
G. Scarpetta
Keyword(s):  
Black Hole ◽  
Gravitational Lensing ◽  
Strong Field ◽  
Field Limit ◽  
Strong Field Limit

Role of deficit solid angle and quintessence-like matter in strong field gravitational lensing

2016 ◽  
Vol 31 (01) ◽  
pp. 1650006
Author(s):  
Jin-Ling Geng ◽  
Yu Zhang ◽  
En-Kun Li ◽  
Peng-Fei Duan
Keyword(s):  
Black Hole ◽  
Gravitational Lensing ◽  
Strong Field ◽  
Solid Angle ◽  
Angular Position ◽  
Schwarzschild Black Hole ◽  
Field Limit ◽  
Eos Parameter ◽  
Strong Gravitational Lensing ◽  
Strong Field Limit

Using the strong field limit approach, the strong field gravitational lensing in a black hole with deficit solid angle (DSA) and surrounded by quintessence-like matter (QM) has been investigated. The results show that the DSA [Formula: see text], the energy density of QM [Formula: see text] and the equation of state (EOS) parameter [Formula: see text] have some distinct effects on the strong field gravitational lensing. As [Formula: see text] or [Formula: see text] increases, the deflection angle and the strong field limit coefficients all increase faster and faster. Moreover, the evolution of the main observables also has been studied, which shows that the curves at [Formula: see text] are more steepy than those of [Formula: see text]. Compared with the Schwarzschild black hole, the black hole surrounded by QM has smaller relative magnitudes, and at [Formula: see text] both the angular position and angular separation are slightly bigger than those of Schwarzschild black hole, but when [Formula: see text], the angular position and the relative magnitudes all diminish significantly. Therefore, by studying the strong gravitational lensing, we can distinguish the black hole with a DSA and surrounded by QM from the Schwarzschild black hole and the effects of the DSA and QM on the strong gravitational lensing by black holes can be known better.

scholarly journals Null Geodesics and Strong Field Gravitational Lensing in a String Cloud Background

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
M. Sharif ◽  
Sehrish Iftikhar
Keyword(s):  
Black Hole ◽  
Gravitational Lensing ◽  
Galactic Center ◽  
Deflection Angle ◽  
Orbital Motion ◽  
Strong Field ◽  
Schwarzschild Black Hole ◽  
Field Limit ◽  
Null Geodesics ◽  
Supermassive Black Hole

This paper is devoted to studying two interesting issues of a black hole with string cloud background. Firstly, we investigate null geodesics and find unstable orbital motion of particles. Secondly, we calculate deflection angle in strong field limit. We then find positions, magnifications, and observables of relativistic images for supermassive black hole at the galactic center. We conclude that string parameter highly affects the lensing process and results turn out to be quite different from the Schwarzschild black hole.

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.

scholarly journals Development of singularities of the Skyrme model

2020 ◽  
Vol 17 (01) ◽  
pp. 61-73
Author(s):  
Michael McNulty
Keyword(s):  
Sigma Model ◽  
Blow Up ◽  
Strong Field ◽  
Skyrme Model ◽  
Nonlinear Sigma Model ◽  
Field Limit ◽  
Wave Maps ◽  
Self Similar ◽  
Similar Solutions ◽  
Strong Field Limit

The Skyrme model is a geometric field theory and a quasilinear modification of the Nonlinear Sigma Model (Wave Maps). In this paper, we study the development of singularities for the equivariant Skyrme Model, in the strong-field limit, where the restoration of scale invariance allows us to look for self-similar blow-up behavior. After introducing the Skyrme Model and reviewing what’s known about formation of singularities in equivariant Wave Maps, we prove the existence of smooth self-similar solutions to the [Formula: see text]-dimensional Skyrme Model in the strong-field limit, and use that to conclude that the solution to the corresponding Cauchy problem blows-up in finite time, starting from a particular class of everywhere smooth initial data.

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