71 research outputs found
Thermodynamic extended phase space and criticality of black holes at Pure Lovelock gravity
In this work the \textit{chemistry} of asymptotically AdS black hole, charged
and uncharged, solutions of Pure Lovelock gravity is discussed. For this the
mass parameter of black holes is identified with the enthalpy of the system
together with the promotion of the cosmological constant to a thermodynamics
variable proportional to the \textit{pressure} of the system. The equations of
state for both, charged and uncharged, are obtained. It is shown that the
charged case behaves as a Van der Waals fluid. The existence of a first order
phase transition between small stable/large stable black hole, which is a
reminiscent of the liquid/gas transition, is found. The critical exponents of
the thermal evolution, for different cases of interest, are similar to those of
the Van der Waals fluid
Magnetic Mass in 4D AdS Gravity
We provide a fully-covariant expression for the diffeomorphic charge in 4D
anti-de Sitter gravity, when the Gauss-Bonnet and Pontryagin terms are added to
the action. The couplings of these topological invariants are such that the
Weyl tensor and its dual appear in the on-shell variation of the action, and
such that the action is stationary for asymptotic (anti) self-dual solutions in
the Weyl tensor. In analogy with Euclidean electromagnetism, whenever the
self-duality condition is global, both the action and the total charge are
identically vanishing. Therefore, for such configurations the magnetic mass
equals the Ashtekhar-Magnon-Das definition.Comment: 21 pages, no figures; one reference added; final version for PR
Boundary conditions in first order gravity: Hamiltonian and Ensemble
In this work two different boundary conditions for first order gravity,
corresponding to a null and a negative cosmological constant respectively, are
studied. Both boundary conditions allows to obtain the standard black hole
thermodynamics. Furthermore both boundary conditions define a canonical
ensemble. Additionally the quasilocal energy definition is obtained for the
null cosmological constant case.Comment: To be published in Phys, Rev.
Conformal Gravity from AdS/CFT mechanism
We explicitly calculate the induced gravity theory at the boundary of an
asymptotically Anti-de Sitter five dimensional Einstein gravity. We also
display the action that encodes the dynamics of radial diffeomorphisms. It is
found that the induced theory is a four dimensional conformal gravity plus a
scalar field. This calculation confirms some previous results found by a
different approach.Comment: Revtex 8 pages, To be published in Phys. Rev.
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