arXiv subjects

Galin G. Gyulchev

Publications and source records attributed to Galin G. Gyulchev.

2 recordsLinked to original sources

arXiv2012

Quasiperiodic oscillations and Tomimatsu-Sato δ = 2 space-time

We model the spacetime of low-mass X-ray binaries with the Tomimatsu-Sato δ = 2 (TS2) metric and study the properties of the orbital and the epicyclic frequencies. The numerical analysis shows that the properties of the characteristic frequencies of oscillation do not differ qualitatively from those of the Kerr black hole. Estimates for the angular momenta of the three stellar mass black hole candidates GRO 1655-40, XTE 1550-564 and GRS 1915+105 are made with the application of the nonlinear resonance model. We find agreement between the predictions based on the 3 : 2 nonlinear resonance model for a TS2 background and the current estimates found in the literature.

astro-ph.HE↗

arXiv2010

Connection between black-hole quasinormal modes and lensing in the strong deflection limit

The purpose of the current Letter is to give some relations between gravitational lensing in the strong-deflection limit and the frequencies of the quasinormal modes of spherically symmetric, asymptotically flat black holes. On the one side, the obtained relations can give a physical interpretation of the strong-deflection limit parameters. On the other side, they also give an alternative method for the measurement of the frequencies of the quasinormal modes of spherically symmetric, asymptotically flat black holes. They could be applied to the localization of the sources of gravitational waves and could tell us what frequencies of the gravitational waves we could expect from a black hole acting simultaneously as a gravitational lens and a source of gravitational waves.

gr-qc↗