Tidal Forces in Cold Black Hole Spacetimes

TL;DR

This paper examines tidal forces in various static black hole solutions, revealing divergences at horizons in cold black holes and presenting a Brans-Dicke model with finite tidal forces at the horizon.

Contribution

It identifies divergence issues in cold black hole horizons and introduces a Brans-Dicke solution with non-diverging tidal forces, improving understanding of black hole horizon properties.

Findings

Tidal forces diverge at cold black hole horizons.

Kruskal-like extensions do not remove singularities in CBHs.

A Brans-Dicke CBH solution with finite tidal forces at the horizon.

Abstract

We investigate here the behavior of a few spherically symmetric static acclaimed black hole solutions in respect of tidal forces in the geodesic frame. It turns out that the forces diverge on the horizon of cold black holes (CBH) while for ordinary ones, they do not. It is pointed out that Kruskal-like extensions do not render the CBH metrics nonsingular. We present a CBH that is available in the Brans-Dicke theory for which the tidal forces do not diverge on the horizon and in that sense it is a better one.