Strong gravitational lensing in hairy Schwarzschild background

Jha, Sohan Kumar; Rahaman, A.

doi:10.1140/epjp/s13360-023-03650-w

Cited by 5 publications

(1 citation statement)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Their study aimed to derive precise expressions for lensing observables pertaining to images formed from within the photon sphere and then compared these results with images formed from outside the photon sphere. The astrophysical implications concerning various observables like image position, separation, magnification, the occurrence of Einstein rings and time delays in the formation of relativistic images have been investigated in connection with several supermas-sive black holes [75][76][77][78][79][80][81][82][83][84][85][86][87][88]. Virbhadra and Keeton investigated the time delay and magnification centroid caused by gravitational lensing from black holes and naked singularities [89].…”

Section: Introductionmentioning

confidence: 99%

Strong gravitational lensing by $$Sgr A^$$ and $$M87^$$ black holes embedded in dark matter halo exhibiting string cloud and quintessential field

Molla,

Chaudhary,

Mustafa

et al. 2024

Eur. Phys. J. C

View full text Add to dashboard Cite

We investigate the strong gravitational lensing phenomena caused by a black hole with a dark matter halo in the presence of cloud string and quintessence. This study examines strong gravitational lensing with two significant dark matter models: the universal rotation curve model and the cold dark matter model. To do this, we first numerically estimate the strong lensing coefficients and strong deflection angles for both the universal rotation curve and cold dark matter models. It is observed that the deflection angle, denoted as $$\alpha _D$$ α D , increases with the parameter $$\alpha $$ α while holding the value of $$2M \gamma $$ 2 M γ constant. Additionally, it increases with the parameter $$2M \gamma $$ 2 M γ while keeping the value of $$\alpha $$ α constant. The strong deflection angle $$\alpha _D$$ α D , for the black hole with a dark matter halo, with parameters $$\alpha $$ α and $$2\,M \gamma $$ 2 M γ , greatly enhances the gravitational bending effect and surpasses the corresponding case of the standard Schwarzschild black hole ($$A=B=0=\alpha =2M\gamma $$ A = B = 0 = α = 2 M γ ). Furthermore, we investigate the astrophysical consequences through strong gravitational lensing observations, using examples of two supermassive black holes, namely $$M87^{*}$$ M 87 ∗ and $$Sgr A^{*}$$ S g r A ∗ , located at the center of nearby galaxies. It is observed that black holes with dark matter halos in the presence of cloud string and quintessence can be quantitatively distinguished and characterized from the standard Schwarzschild black hole ($$A=B=0=\alpha =2M\gamma $$ A = B = 0 = α = 2 M γ ). The findings in our analysis suggest that observational tests for black holes influenced by dark matter halos, cloud string and quintessence are indeed feasible and viable.

show abstract

Section: Introductionmentioning

confidence: 99%

Strong gravitational lensing by $$Sgr A^$$ and $$M87^$$ black holes embedded in dark matter halo exhibiting string cloud and quintessential field

Molla,

Chaudhary,

Mustafa

et al. 2024

Eur. Phys. J. C

View full text Add to dashboard Cite

show abstract

Investigating the shadows and strong gravitational lensing of modified Bardeen black holes

Molla,

Ali,

Debnath

et al. 2024

Phys. Scr.

View full text Add to dashboard Cite

This study is dedicated to exploring the distinctive observational features affected by the modified Bardeen black hole through meticulous analysis of its shadow and strong gravitational lensing observations. We thoroughly investigated the impact of the black hole's parameters q, g and $\mu$ on its shadow radius through numerical simulations and graphical representations. Utilizing the Event Horizon Telescope (EHT) data, we constrained the parameters $q$ and $\mu$ of the modified Bardeen black hole within specific ranges: $-1.24 M^2\leq \mu \leq 8M^2$ and $0\leq |q|\leq 1.38M $ for $M87^*$; and $-3.52 M^2\leq \mu \leq 19.6M^2$ and $0\leq |q|\leq 0.8M $ for $Sgr A^*$, while maintaining the fixed value $g=0.4M$. This restriction of the ($\mu$, $q$) parameter space by the EHT findings illustrates the viability of modified Bardeen black holes as astrophysical candidates. Additionally, we study strong gravitational lensing and its various observables for the modified Bardeen black hole, comparing its behavior to other astrophysical black holes such as the Schwarzschild ($\mu=0=q$) and Bardeen ($\mu=0$) black holes. By examining the astrophysical ramifications through strong gravitational lensing, considering supermassive black holes at the center of nearby galaxies, we uncovered that the modified Bardeen black hole exhibits distinct characteristics, offering a quantitative distinction from other black holes such as the Schwarzschild and Bardeen black holes. These findings in astrophysical consequences provide a promising pathway to differentiate the modified black hole from its counterparts in the realm of general relativity.

show abstract

Probing dark fluids and modified gravity with gravitational lensing

Perivolaropoulos

Antoniou

Papadopoulos

2023

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

We generalize the Rindler-Ishak (2007) result for the lensing deflection angle in a SdS spacetime, to the case of a general spherically symmetric fluid beyond the cosmological constant. We thus derive an analytic expression to first post-Newtonian order for the lensing deflection angle in a general static spherically symmetric metric of the form $ds^2 = f(r)dt^{2} -\frac{dr^{2}}{f(r)}-r^{2}(d\theta ^2 +\sin ^2 \theta d\phi ^2)$ with $f(r) = 1 - \frac{2m}{r}-\sum _{i} b_i\,\, r_0^{-q_i}\,\, \left( \frac{r_0}{r}\right)^{q_i}$ where r0 is the lensing impact parameter, $b_i\ll r_0^{q_i}$, m is the mass of the lens and qi are real arbitrary constants related to the properties of the fluid that surrounds the lens or to modified gravity. This is a generalization of the well known Kiselev black hole metric. The approximate analytic expression of the deflection angle is verified by an exact numerical derivation and in special cases it reduces to results of previous studies. The density and pressure of the spherically symmetric fluid that induces this metric is derived in terms of the constants bi. The Kiselev case of a Schwarzschild metric perturbed by a general spherically symmetric dark fluid (eg vacuum energy) is studied in some detail and consistency with the special case of Rindler Ishak result is found for the case of a cosmological constant background. Observational data of the Einstein radii from distant clusters of galaxies lead to observational constraints on the constants bi and through them on the density and pressure of dark fluids, field theories or modified gravity theories that could induce this metric.

show abstract

Strong gravitational lensing in hairy Schwarzschild background

Cited by 5 publications

References 47 publications

Strong gravitational lensing by $$Sgr A^$$ and $$M87^$$ black holes embedded in dark matter halo exhibiting string cloud and quintessential field

Strong gravitational lensing by $$Sgr A^$$ and $$M87^$$ black holes embedded in dark matter halo exhibiting string cloud and quintessential field

Investigating the shadows and strong gravitational lensing of modified Bardeen black holes

Probing dark fluids and modified gravity with gravitational lensing

Contact Info

Product

Resources

About

Strong gravitational lensing in hairy Schwarzschild background

Cited by 5 publications

References 47 publications

Strong gravitational lensing by $$Sgr A^*$$ and $$M87^*$$ black holes embedded in dark matter halo exhibiting string cloud and quintessential field

Strong gravitational lensing by $$Sgr A^*$$ and $$M87^*$$ black holes embedded in dark matter halo exhibiting string cloud and quintessential field

Investigating the shadows and strong gravitational lensing of modified Bardeen black holes

Probing dark fluids and modified gravity with gravitational lensing

Contact Info

Product

Resources

About

Strong gravitational lensing by $$Sgr A^$$ and $$M87^$$ black holes embedded in dark matter halo exhibiting string cloud and quintessential field

Strong gravitational lensing by $$Sgr A^$$ and $$M87^$$ black holes embedded in dark matter halo exhibiting string cloud and quintessential field