Sp(4,R)/GL(2,R) Matrix Structure of Geodesic Solutions for Einstein--Maxwell--Dilaton--Axion Theory

TL;DR

This paper introduces a matrix operator framework for generating geodesic solutions in Einstein--Maxwell--dilaton--axion theory, encompassing black holes and naked singularities with various charges.

Contribution

It develops a new $Sp(4,R)/GL(2,R)$ matrix approach to derive a broad class of solutions in the theory, including special cases like black holes and naked singularities.

Findings

Contains solutions with nontrivial mass, NUT, and charges.

Includes Majumdar--Papapetrou--like black holes.

Features massless asymptotically nonflat naked singularities.

Abstract

The constructed $Sp(4,R)/GL(2,R)$ matrix operator defines the family of isotropic geodesic containing vacuum point lines in the target space of the stationary D=4 Einstein--Maxwell--dilaton--axion theory. This operator is used to derive a class of solutions which describes a point center system with nontrivial values of mass, parameter NUT, as well as electric, magnetic, dilaton and axion charges. It is shown that this class contains both particular solutions Majumdar--Papapetrou--like black holes and massless asymptotically nonflat naked singularities.