Einstein-Maxwell-Dilaton-Axion mass formulas for black holes with struts and strings

TL;DR

This paper derives mass formulas for stationary axisymmetric black hole solutions in Einstein-Maxwell-dilaton-axion theory, incorporating contributions from rods, strings, and fields, and offers new insights into black hole thermodynamics.

Contribution

It introduces novel mass formulas for EMDA black holes with rods and strings using a sigma model approach, extending previous methods to include Dirac and Misner strings.

Findings

Mass formulas relate asymptotic quantities to rod and string contributions.

Results provide an alternative interpretation of black hole thermodynamics.

Applicable to multiple black holes with struts and strings.

Abstract

Mass formulas are obtained for stationary axisymmetric solutions of the Einstein-Maxwell dilaton-axion theory, which have a regular rod structure on the axis of symmetry. Asymptotic mass, angular momentum and charge are expressed as the sums of masses, angular momenta and charges of rods dressed with field contributions. The calculation is based on a three-dimensional sigma model representation of the stationary EMDA system and the Tomimatsu approach proposed for the Einstein-Maxwell system. Our results provide an alternative interpretation of mass formulas and thermodynamics for black holes with Dirac and Misner strings. It is also applicable to aligned multiple black holes with struts.