The phase structure of black D1/D5 (F/NS5) system in canonical ensemble

TL;DR

This paper investigates how combining D1/D5 (or F/NS5) black branes alters their phase structure, revealing a transition from simple to complex phase diagrams with liquid-gas type behavior.

Contribution

It demonstrates that the phase structure of black D1/D5 and F/NS5 systems becomes richer when combined, introducing van der Waals-Maxwell type phase transitions, unlike their individual components.

Findings

Delocalized charged black D-strings share phase structure with D5 branes.

Combining D1/D5 or F/NS5 leads to a richer phase diagram with liquid-gas behavior.

Adding D-strings or F-strings effectively increases the transverse dimensions.

Abstract

In this paper, we explore means which can be used to change qualitatively the phase structure of charged black systems. For this, we consider a system of black D1/D5 (or its S-dual F/NS5). We find that the delocalized charged black D-strings (F-strings) alone share the same phase structure as the charged black D5 branes (NS5-branes), having no van der Waals-Maxwell liquid-gas type. However, when the two are combined to form D1/D5 (F/NS5), the resulting phase diagram has been changed dramatically to a richer one, containing now the above liquid-gas type. The effect of adding the charged D-strings (F-strings) on the phase structure can also be effectively described as a slight increase of the transverse dimensions to the original D5 (NS5). This may be viewed as a connection between a brane charge and a fraction of spatial dimension at least in a thermodynamical sense.