On the temperature dependence of the absorption cross section for black holes in string theory

TL;DR

This paper investigates how the low frequency absorption cross section of black holes in string theory depends on temperature, especially considering alpha' corrections and classical solutions, revealing a universal 1/T_H dependence.

Contribution

It derives a formula for the temperature dependence of the absorption cross section including alpha' corrections and applies it to specific black hole solutions in string theory.

Findings

Absorption cross section exhibits a 1/T_H dependence with alpha' corrections.

The formula smoothly approaches the extremal limit in classical solutions.

Application to corrected solutions confirms the theoretical predictions.

Abstract

We study the low frequency absorption cross section of spherically symmetric nonextremal d-dimensional black holes. In the presence of alpha' corrections, this quantity must have an explicit dependence on the Hawking temperature of the form 1/T_H. This property of the low frequency absorption cross section is shared by the D1-D5 system from type IIB superstring theory already at the classical level, without alpha' corrections. We apply our formula to the simplest example, the classical d-dimensional Reissner-Nordstrom solution, checking that the obtained formula for the cross section has a smooth extremal limit. We also apply it for a d-dimensional Tangherlini-like solution with alpha'^3 corrections.