An Equivalence Between Momentum and Charge in String Theory

TL;DR

This paper demonstrates a duality in string theory where momentum and charge are interchangeable, revealing equivalences between different black string solutions and plane waves.

Contribution

It establishes a novel equivalence between momentum and charge in string theory solutions, linking charged black strings to boosted uncharged strings and extremal strings to plane waves.

Findings

Charged black strings are equivalent to boosted uncharged black strings.

Extremal black strings correspond to plane fronted waves.

Spacetime duality interchanges momentum and axion charge.

Abstract

It is shown that for a translationally invariant solution to string theory, spacetime duality interchanges the momentum in the symmetry direction and the axion charge per unit length. As one application, we show explicitly that charged black strings are equivalent to boosted (uncharged) black strings. The extremal black strings (which correspond to the field outside of a fundamental macroscopic string) are equivalent to plane fronted waves describing strings moving at the speed of light.