Horizon regularity and dilaton coupling quantization in EMD dyons

TL;DR

This paper investigates extremal dyonic solutions in Einstein-Maxwell-Dilaton theory, revealing a quantization condition linked to horizon regularity and exploring their BPS-like properties without known supersymmetric embeddings.

Contribution

It demonstrates the existence of a discrete sequence of coupling constants where regular extremal dyons occur and analyzes their properties in relation to BPS configurations.

Findings

Quantization condition from horizon regularity

Existence of a discrete sequence of coupling constants

Dyons satisfy no-force condition and have flat reduced spaces

Abstract

Four-dimensional Einstein-Maxwell-Dilaton theory admits asymptotically flat extremal dyonic solutions for an infinite discrete sequence of the coupling constant values. The quantization condition arises as consequence of regularity of the dilaton function at the event horizon. These dyons satisfy the no-force condition and have flat reduced three spaces like true BPS configurations, but no supersymmetric embeddings are known except for some cases of lower values of the coupling sequence.