# Phenomenological Extension for Tidal Charge Black Hole

## TL;DR

This paper proposes a phenomenological extension of the tidal charge black hole solution, generalizing the Reissner-Nordstrom metric to include effects beyond general relativity, consistent with Sgr A* data.

## Contribution

It introduces a new metric that extends existing black hole solutions to incorporate additional gravitational effects beyond general relativity.

## Key findings

- The proposed metric aligns with empirical data on Sgr A*.
- It predicts the size of the black hole shadow.
- It determines the innermost stable circular orbit radius.

## Abstract

A simple phenomenological extension of the black hole solution with tidal charge is proposed. Empirical data on the Sgr A* is consistent with the suggested metric which serves as a generalisation of the Reissner-Nordstrom one. Such a generalisation includes the leading effects beyond general relativity so, the discussed metric can explain wider range of gravitational effects. We discuss physical features of an object described by the proposed metric, namely, the size of its shadow and the innermost stable circular orbit radius.