Exploring antisymmetric tensor effects on black hole shadows and quasinormal frequencies

TL;DR

This paper investigates how antisymmetric tensor effects influence black hole shadows and quasinormal modes, revealing that Lorentz violation and cosmological constant significantly alter these phenomena, with implications for observational data interpretation.

Contribution

It provides a detailed analysis of antisymmetric tensor effects on black hole properties, including photon spheres, shadows, and quasinormal frequencies, considering Lorentz symmetry breaking and cosmological constant influences.

Findings

Lorentz violation reduces photon sphere and shadow radius.

Increasing cosmological constant expands shadow radius.

Higher $\Lambda$ leads to less damping in gravitational wave modes.

Abstract

This study explores the impact of antisymmetric tensor effects on spherically symmetric black holes, investigating photon spheres, shadows, emission rate and quasinormal frequencies in relation to a parameter which triggers the Lorentz symmetry breaking. We examine these configurations without and with the presence of a cosmological constant. In the first scenario, the Lorentz violation parameter, denoted as $\lambda$, plays a pivotal role in reducing both the photon sphere and the shadow radius, while also leading to a damping effect on quasinormal frequencies. Conversely, in the second scenario, as the values of the cosmological constant ($\Lambda$) increase, we observe an expansion in the shadow radius. Also, we provide the constraints of the shadows based on the analysis observational data obtained from the Event Horizon Telescope (EHT) focusing on Sagittarius $A^{*}$ shadow images. Additionally, with the increasing $\Lambda$, the associated gravitational wave frequencies exhibit reduced damping modes.