On non-uniform smeared black branes

TL;DR

This paper studies charged dilatonic black p-branes smeared on a circle, deriving perturbations and critical wavelengths, and analyzes their thermodynamic stability, revealing dimension-dependent favorability of non-uniform solutions.

Contribution

It constructs non-uniform solutions for smeared black branes via perturbation theory and examines their thermodynamic stability across different spacetime dimensions.

Findings

Critical wavelength for instability determined.

Non-uniform smeared branes are entropically disfavored in certain dimensions.

Thermodynamic favorability depends on the ensemble and dimension.

Abstract

We investigate charged dilatonic black $p$-branes smeared on a transverse circle. The system can be reduced to neutral vacuum black branes, and we perform static perturbations for the reduced system to construct non-uniform solutions. At each order a single master equation is derived, and the Gregory-Laflamme critical wavelength is determined. Based on the non-uniform solutions, we discuss thermodynamic properties of this system and argue that in a microcanonical ensemble the non-uniform smeared branes are entropically disfavored even near the extremality, if the spacetime dimension is $D \le 13 +p$, which is the critical dimension for the vacuum case. However, the critical dimension is not universal. In a canonical ensemble the vacuum non-uniform black branes are thermodynamically favorable at $D > 12+p$, whereas the non-uniform smeared branes are favorable at $D > 14+p$ near the extremality.