Alex Giacomini

Scalar field perturbations in asymptotically Lifshitz black holes

We consider scalar field perturbations about asymptotically Lifshitz black holes with dynamical exponent

Black holes with primary hair in gauged N = 8 supergravity

z

Dynamical analysis of an integrable cubic Galileon cosmological model

in

Gribov pendulum in the Coulomb gauge on curved spaces

D

Cosmological dynamics in higher-dimensional Einstein–Gauss–Bonnet gravity

dimensions. We show that, for suitable boundary conditions, these Lifshitz black holes are stable under scalar field perturbations. For

Black holes with gravitational hair in higher dimensions

z=2

BTZ-like black holes in even dimensional Lovelock theories

, we explicitly compute the quasinormal mode frequencies, which result to be purely imaginary, and then obtain the damping-off of the scalar field perturbation in these backgrounds. The general analysis includes, in particular, the

Poisson algebra of diffeomorphism generators in a space-time containing a bifurcation

z=3

General relativity with small cosmological constant from spontaneous compactification of Lovelock theory in vacuum

black hole solution of three-dimensional massive gravity.

Dynamical symmetries in Brans-Dicke cosmology

A bstractIn this paper, we analyze the static solutions for the U(1)4 consistent truncation of the maximally supersymmetric gauged supergravity in four dimensions. Using a new parametrization of the known solutions it is shown that for fixed charges there exist three possible black hole configurations according to the pattern of symmetry breaking of the (scalars sector of the) Lagrangian. Namely a black hole without scalar fields, a black hole with a primary hair and a black hole with a secondary hair respectively. This is the first, exact, example of a black hole with a primary scalar hair, where both the black hole and the scalar fields are regular on and outside the horizon. The configurations with secondary and primary hair can be interpreted as a spontaneous symmetry breaking of discrete permutation and reflection symmetries of the action. It is shown that there exist a triple point in the thermodynamic phase space where the three solution coexist. The corresponding phase transitions are discussed and the free energies are written explicitly as function of the thermodynamic coordinates in the uncharged case. In the charged case the free energies of the primary hair and the hairless black hole are also given as functions of the thermodynamic coordinates.