Complement to thermodynamics of dyonic Taub-NUT-AdS spacetime

Abstract

We examine the thermodynamics of Euclidean dyonic Taub-Nut/Bolt-AdS4 black holes for a variety of horizon geometries to understand how gauge field regularity conditions influence the thermodynamic relations. We find several distinct features that distinguish the NUT-charged case from its dyonic Reissner-Nordstrom counterpart. For the Nut solution, the gauge field vanishes at the horizon and so regularity is ensured. For the Bolt solution we find that the norm of the gauge field is required to vanish at the horizon in order to satisfy both regularity and the first law of thermodynamics. This regularity condition yields a constraint on the electric and magnetic charges and so reduces cohomogeneity of the system; for spherical horizons, the regularity condition removing the Misner string singularity further reduces cohomogeneity. We observe that bolt solutions with increasing electric charge have positive heat capacity, but upon turning on the magnetic charge to make the solution dyonic, we find that the properties of the uncharged one are retained, having both positive and negative heat capacity. We also study the extremal Bolt solution, finding that Misner string disappears at the horizon in the zero temperature limit. We find that the extremal solution has finite-temperature-like behaviour, with the electric potential playing a role similar to temperature.

Gravitational instantons with conformally coupled scalar fields

“…Besides the (anti-)self dual Eguchi-Hanson instanton in the conformally invariant case, there is an additional Taub-NUT/Bolt-AdS solution with a weakened AdS asymptotics. This can be obtained by considering the line element (21) as a metric ansatz and noticing that field equations in the conformally invariant case are solved by…”

“…This solution is usually interpreted as a gravitational dyon since the NUT charge plays the role of a gravitomagnetic monopole, sourcing the magnetic part of the Weyl tensor [16][17][18][19]. In presence of Maxwell fields, the first charged Taub-NUT solution was obtained by Brill in [20] and different aspects of their thermodynamics have been recently studied [21,22]. 1 Holographic aspects of rotating Taub-NUT-AdS spaces have been studied through the Kerr/CFT correspondence [27][28][29][30] and it has been demonstrated that this solution describes holographic fluids with nontrivial vorticity [31][32][33][34][35].…”

Conformal scalar NUT-like dyons in conformal electrodynamics

“…Thermodynamics of the black hole with NUT charge have been studied recently in [25][26][27][28][29][30][31], especially in [7] for the Taub-NUT solution in Einstein case with conformal electrodynamics, which are main references for our study here. The event horizon of the NUTty dyon black hole generated by the Killing vector ξ = ∂ t is…”

Gravitational instantons with conformally coupled scalar fields

“…This solution is usually interpreted as a gravitational dyon since the NUT charge plays the role of a gravitomagnetic monopole, sourcing the magnetic part of the Weyl tensor [16][17][18][19]. In presence of Maxwell fields, the first charged Taub-NUT JHEP05(2022)110 solution was obtained by Brill in [20] and different aspects of their thermodynamics have been recently studied [21,22]. 1 Holographic aspects of rotating Taub-NUT-AdS spaces have been studied through the Kerr/CFT correspondence [27][28][29][30] and it has been demonstrated that this solution describes holographic fluids with nontrivial vorticity [31][32][33][34][35].…”