27 research outputs found
Charged Lifshitz Black Holes
We investigate modifications of the Lifshitz black hole solutions due to the
presence of Maxwell charge in higher dimensions for arbitrary and any
topology. We find that the behaviour of large black holes is insensitive to the
topology of the solutions, whereas for small black holes significant
differences emerge. We generalize a relation previously obtained for neutral
Lifshitz black branes, and study more generally the thermodynamic relationship
between energy, entropy, and chemical potential. We also consider the effect of
Maxwell charge on the effective potential between objects in the dual theory.Comment: Latex, 28 pages, 14 figures, some references adde
Thermodynamic Instability of Black Holes of Third Order Lovelock Gravity
In this paper, we compute the mass and the temperature of the uncharged black
holes of third order Lovelock gravity and compute the entropy through the use
of first law of thermodynamics. We perform a stability analysis by studying the
curves of temperature versus the mass parameter, and find that there exists an
intermediate thermodynamically unstable phase for black holes with hyperbolic
horizon. The existence of this unstable phase for the uncharged topological
black holes of third order Lovelock gravity does not occur in the lower order
Lovelock gravity. We also perform a stability analysis for a spherical,
7-dimensional black hole of Lovelock gravity and find that while these kinds of
black holes for small values of Lovelock coefficients have an intermediate
unstable phase, they are stable for large values of Lovelock coefficients. We
also find that there exists an intermediate unstable phase for these black
holes in higher dimensions. This stability analysis shows that the
thermodynamic stability of black holes with curved horizons is not a robust
feature of all the generalized theories of gravity.Comment: 16 pages, 8 figure
Corner contributions to holographic entanglement entropy
The entanglement entropy of three-dimensional conformal field theories
contains a universal contribution coming from corners in the entangling
surface. We study these contributions in a holographic framework and, in
particular, we consider the effects of higher curvature interactions in the
bulk gravity theory. We find that for all of our holographic models, the corner
contribution is only modified by an overall factor but the functional
dependence on the opening angle is not modified by the new gravitational
interactions. We also compare the dependence of the corner term on the new
gravitational couplings to that for a number of other physical quantities, and
we show that the ratio of the corner contribution over the central charge
appearing in the two-point function of the stress tensor is a universal
function for all of the holographic theories studied here. Comparing this
holographic result to the analogous functions for free CFT's, we find fairly
good agreement across the full range of the opening angle. However, there is a
precise match in the limit where the entangling surface becomes smooth, i.e.,
the angle approaches , and we conjecture the corresponding ratio is a
universal constant for all three-dimensional conformal field theories. In this
paper, we expand on the holographic calculations in our previous letter
arXiv:1505.04804, where this conjecture was first introduced.Comment: 62 pages, 6 figures, 1 table; v2: minor modifications to match
published version, typos fixe