Temperature of D3-branes off extremality

TL;DR

This paper investigates non-extremal rotating D3-branes by solving scalar wave equations in their supergravity backgrounds, revealing non-equilibrium thermal behavior and contributing to understanding discrepancies between supergravity and conformal field theory results.

Contribution

It provides a detailed analysis of scalar absorption in non-extremal D3-brane backgrounds, highlighting the non-equilibrium nature of open string modes off extremality.

Findings

Absorption coefficients resemble black-hole gray-body factors.

Fields do not remain in thermal equilibrium off extremality.

Two different temperature parameters characterize the system.

Abstract

We discuss non-extremal rotating D3-branes. We solve the wave equation for scalars in the supergravity background of certain distributions of branes and compute the absorption coefficients. The form of these coefficients is similar to the gray-body factors associated with black-hole scattering. They are given in terms of two different temperature parameters, indicating that fields (open string modes) do not remain in thermal equilibrium as we move off extremality. This should shed some light on the origin of the disagreement between the supergravity and conformal field theory results on the free energy of a system of non-coincident D-branes.