2025/08/19 by Lu, Guan-Yi, Yang, Meng-Nan, Lu, H. · 2 citations
#FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #High Energy Physics - Theory (hep-th)
paper · doi:10.48550/arxiv.2508.14158
We consider Einstein gravity minimally coupled to two Maxwell fields and one (real) dilaton scalar. We study the electrically-charged spherically-symmetric and static solutions that are asymptotic to Minkowski spacetime. General solutions are described by four independent parameters: mass M, two electric charges (Q1,Q2) and the scalar charge Σ. For black holes, the scalar charge is not independent, but a function of (M,Q1,Q2). We provide a set of formulae relating the mass to the charges, which allows us to determine Σ(M,Q1,Q2) without having to solve the black hole equations. Our results confirm the weaker version of the no-hair theorem conjecture involving one real scalar: it can be turned on in a black hole, but it does not have a continuous independent hairy parameter.