Asymptotic Structure of Einstein-Maxwell-Dilaton Theory and Its Five Dimensional Origin

TL;DR

The paper analyzes the asymptotic structure of four-dimensional Einstein-Maxwell-dilaton theory in Bondi gauge, revealing three independent news functions corresponding to gravitational, electromagnetic, and scalar radiation and deriving a generalized Bondi mass-loss formula. By uplifting the four-dimensional solutions to five dimensions through Kaluza-Klein reduction (a=√3), it demonstrates that the same asymptotic symmetry algebra arises in five-dimensional pure Einstein gravity. The work provides explicit series expansions for the fields, clarifies the role of the dilaton coupling in radiative dynamics, and shows that the four- and five-dimensional theories share identical asymptotic symmetries, thereby offering a bridge between lower-dimensional radiative data and higher-dimensional gravitational structure. These results have implications for holography, memory effects, and the study of higher-dimensional gravity from a Bondi framework.

Abstract

We consider Einstein-Maxwell-dilaton theory in four dimensions including the Kaluza-Klein theory and obtain the general asymptotic solutions in Bondi gauge. We find that there are three different types of news functions representing gravitational, electromagnetic, and scalar radiations. The mass density at any angle of the system can only decrease whenever there is any type of news function. The solution space of the Kaluza-Klein theory is also lifted to five dimensions. We also compute the asymptotic symmetries in both four dimensional Einstein-Maxwell-dilaton theory and five dimensional pure Einstein theory. We find that the symmetry algebras of the two theories are the same.