Gravitational instantons with conformally coupled scalar fields

• DOI: 10.1007/jhep05(2022)110
• Publication Date: 2022-05-18T16:18:28Z
• Authors: José Barrientos; Adolfo Cisterna; Cristóbal Corral; Marcelo Oyarzo
• Keywords: Instanton

We present novel regular Euclidean solutions to General Relativity in presence of Maxwell and conformally coupled scalar fields. In particular, we consider metrics the Eguchi-Hanson Taub-NUT families solve field equations analytically. The have nontrivial topology labeled by Hirzebruch signature Euler characteristic that compute explicitly. find that, although are locally inequivalent with original (anti-)self-dual metric, their asymptotically limit leads same global properties. revisit solution previously found literature, analyze nuts bolts structure, obtain renormalized on-shell action as well topological invariants. Additionally, discuss how get modified higher-curvature corrections respect conformal invariance. invariant case, demonstrate both Noether-Wald charges finite without any reference intrinsic boundary counterterms.