Acena, A., Anabalon, A., Astefanesei, D., & Mann, R. (2014). Hairy planar black holes in higher dimensions. J. High Energy Phys., (1), 21 pp.
Abstract: We construct exact hairy planar black holes in Ddimensional AdS gravity. These solutions are regular except at the singularity and have stressenergy that satisfies the null energy condition. We present a detailed analysis of their thermodynamical properties and show that the first law is satisfied. We also discuss these solutions in the context of AdS/CFT duality and construct the associated cfunction.

Anabalon, A., Astefanesei, D., & Mann, R. (2013). Exact asymptotically flat charged hairy black holes with a dilaton potential. J. High Energy Phys., (10), 22 pp.
Abstract: We find broad classes of exact 4dimensional asymptotically flat black hole solutions in EinsteinMaxwell theories with a nonminimally coupled dilaton and its nontrivial potential. We consider a few interesting limits, in particular, a regular generalization of the dilatonic ReissnerNordstrom solution and, also, smooth deformations of supersymmetric black holes. Further examples are provided for more general dilaton potentials. We discuss the thermodynamical properties and show that the first law is satisfied. In the nonextremal case the entropy depends, as expected, on the asymptotic value of the dilaton. In the extremal limit, the entropy is determined purely in terms of charges and is independent of the asymptotic value of the dilaton. The attractor mechanism can be used as a criterion for the existence of the regular solutions. Since there is a 'competition' between the effective potential and dilaton potential, we also obtain regular extremal black hole solutions with just one U(1) gauge field turned on.

Anabalon, A., Deruelle, N., & Julie, F. L. (2016). EinsteinKatz action,variational principle, Noether charges and the thermodynamics of AdSblack holes. J. High Energy Phys., (8), 15 pp.
Abstract: In this paper we describe 4dimensional gravity coupled to scalar and Maxwell fields by the EinsteinKatz action, that is, the covariant version of the “GammaGamma – GammaGamma” part of the Hilbert action supplemented by the divergence of a generalized “Katz vector”. We consider static solutions of Einstein's equations, parametrized by some integration constants, which describe an ensemble of asymptotically AdS black holes. Instead of the usual Dirichlet boundary conditions, which aim at singling out a specific solution within the ensemble, we impose that the variation of the action vanishes on shell for the broadest possible class of solutions. We will see that, when a longrange scalar “hair” is present, only subfamilies of the solutions can obey that criterion. The KatzBicakLyndenBell (“KBL”) superpotential built on this (generalized) vector will then give straightforwardly the Noether charges associated with the spacetime symmetries (that is, in the static case, the mass). Computing the action on shell, we will see next that the solutions which obey the imposed variational principle, and with Noether charges given by the KBL superpotential, satisfy the Gibbs relation, the Katz vectors playing the role of “counterterms”. Finally, we show on the specific example of dyonic black holes that the subclass selected by our variational principle satisfies the first law of thermodynamics when their mass is de fined by the KBL superpotential.

Concha, P., Merino, N., Miskovic, O., Rodriguez, E., SalgadoRebolledo, P., & Valdivia, O. (2018). Asymptotic symmetries of threedimensional ChernSimons gravity for the Maxwell algebra. J. High Energy Phys., (10), 22 pp.
Abstract: We study a threedimensional ChernSimons gravity theory based on the Maxwell algebra. We find that the boundary dynamics is described by an enlargement and deformation of the bms(3) algebra with three independent central charges. This symmetry arises from a gravity action invariant under the local Maxwell group and is characterized by presence of Abelian generators which modify the commutation relations of the supertranslations in the standard bms(3) algebra. Our analysis is based on the charge algebra of the theory in the BMS gauge, which includes the known solutions of standard asymptotically flat case. The field content of the theory is different than the one of General Relativity, but it includes all its geometries as particular solutions. In this line, we also study the stationary solutions of the theory in ADM form and we show that the vacuum energy and the vacuum angular momentum of the stationary configuration are influenced by the presence of the gravitational Maxwell field.
