scholarly journals Relationship between high-energy absorption cross section and strong gravitational lensing for black hole

2011 ◽  
Vol 84 (4) ◽  
Author(s):  
Shao-Wen Wei ◽  
Yu-Xiao Liu ◽  
Heng Guo
Author(s):  
Ali Övgün

This letter aims to show the connection between the sinc approximation for high-energy absorption cross section and the shadow radius of the spherically symmetric black hole. This connection can give a physical interpretation of the absorption cross section in the eikonal limit parameters. Moreover, the use of this alternative way, one can extract its shadow radius from the absorption cross section in high energy limits to gain more information about the black hole spacetime. Our results indicate that the increasing the value of the shadow radius of the black hole, exponentially increase the the absorption cross section of the black hole in high-energy limits which can be captured by the Event Horizon Telescope (EHT) collaboration.


2018 ◽  
Vol 27 (11) ◽  
pp. 1843012 ◽  
Author(s):  
Carolina L. Benone ◽  
Luiz C. S. Leite ◽  
Luís C. B. Crispino ◽  
Sam R. Dolan

We investigate null geodesics impinging parallel to the rotation axis of a Kerr–Newman black hole, and show that the absorption cross section for a massless scalar field in the eikonal limit can be described in terms of the photon orbit parameters. We compare our sinc and low-frequency approximations with numerical results, showing that they are in excellent agreement.


2009 ◽  
Vol 18 (01) ◽  
pp. 1-11 ◽  
Author(s):  
R. SINI ◽  
V. C. KURIAKOSE

The behavior of a charged scalar field in the RN black hole space–time is studied using the WKB approximation. In the present work, it is assumed that matter waves can be reflected from the event horizon. Using this effect, the Hawking temperature and the absorption cross section for an RN black hole placed in a charged scalar field are calculated. The absorption cross section σabs is found to be inversely proportional to the square of the Hawking temperature of the black hole.


2021 ◽  
Vol 81 (12) ◽  
Author(s):  
Sérgio V. M. C. B. Xavier ◽  
Carolina L. Benone ◽  
Luís C. B. Crispino

AbstractWe investigate the absorption of planar massless scalar waves by a charged rotating stringy black hole, namely a Kerr–Sen black hole. We compute numerically the absorption cross section and compare our results with those of the Kerr–Newman black hole, a classical general relativity solution. In order to better compare both charged black holes, we define the ratio of the black hole charge to the extreme charge as Q. We conclude that Kerr–Sen and Kerr–Newman black holes have a similar absorption cross section, with the difference increasing for higher values of Q.


Sign in / Sign up

Export Citation Format

Share Document