Phase structures of 4D stringy charged black holes in canonical ensemble

TL;DR

This paper investigates the thermodynamic phase structures of 4D charged dilatonic black holes in a cavity within string theory, highlighting the influence of dilaton coupling and dimensional reduction on phase behavior.

Contribution

It provides a comprehensive analysis of how dilaton coupling affects phase structures and compares effects of different dimensional reductions on black hole thermodynamics.

Findings

Dilaton coupling significantly influences phase structures.

Diagonal dimensional reduction preserves phase structure.

Direct dimensional reduction can alter phase structure.

Abstract

We study the thermodynamics and phase structures of the asymptotically flat dilatonic black holes in 4 dimensions, placed in a cavity {\it a la} York, in string theory for an arbitrary dilaton coupling. We consider these charged black systems in canonical ensemble for which the temperature at the wall of and the charge inside the cavity are fixed. We find that the dilaton coupling plays the key role in the underlying phase structures. The connection of these black holes to higher dimensional brane systems via diagonal (double) and/or direct dimensional reductions indicates that the phase structures of the former may exhaust all possible ones of the latter, which are more difficult to study, under conditions of similar settings. Our study also shows that a diagonal (double) dimensional reduction preserves the underlying phase structure while a direct dimensional reduction has the potential to change it.