Related papers: Zero temperature black holes and the failure of se…
The surface gravity for the extreme Reissner-Nordstr\"om black hole is zero suggesting that it has a zero temperature. However, the direct evaluation of the Bogolubov's coefficients, using the standard semi-classical analysis, indicates…
The semiclassical Einstein equations are solved to first order in $\epsilon = \hbar/M^2$ for the case of an extreme or nearly extreme Reissner-Nordstr\"{o}m black hole perturbed by the vacuum stress-energy of quantized free fields. It is…
Semiclassical perturbations to the Reissner-Nordstrom metric caused by the presence of a quantized massive scalar field with arbitrary curvature coupling are found to first order in \epsilon = \hbar/M^2. The DeWitt-Schwinger approximation…
The semiclassical Einstein equations are solved to first order in $\epsilon = \hbar/M^2$ for the case of a Reissner-Nordstr\"{o}m black hole perturbed by the vacuum stress-energy of quantized free fields. Massless and massive fields of spin…
We study Einstein gravity coupled to a massless scalar field in a static spherically symmetric space-time in four dimensions. Black hole solutions exist when the kinetic energy of the scalar field is negative, that is, for a phantom field.…
We investigate the behaviour of a non-commutative radiating Reissner-Nordstrom(Re-No)black hole. We find some interesting results : a). the existence of a minimal non-zero mass to which the black hole can shrink. b). a finite maximum…
New four-dimensional black hole solutions of Brans-Dicke equations with a negative constant $\omega$, coupled to a massless scalar field, are presented. The temperature of these black holes is zero and the horizon area is infinite. An…
Black holes arising in the context of scalar-tensor gravity theories, where the scalar field is non-minimally coupled to the curvature term, have zero surface gravity. Hence, it is generally stated that their Hawking temperature is zero,…
In flat space, the extreme Reissner-Nordstr\o m (RN) black hole is distinguished by its coldness (vanishing Hawking temperature) and its supersymmetry. We examine RN solutions to Einstein-Maxwell theory with a cosmological constant…
We study some physical properties of black holes in Null Aether Theory (NAT)--a vector-tensor theory of gravity. We first review the black hole solutions in NAT and then derive the first law of black hole thermodynamics. The temperature of…
Liberati, Rothman and Sonego have recently showed that objects collapsing into extremal Reissner-Nordstrom black holes do not behave as thermal objects at any time in their history. In particular, a temperature, and hence thermodynamic…
In a recent paper (gr-qc/0002007), Anderson, Hiscock and Taylor claimed that "in all physically realistic cases, macroscopic zero temperature black hole solutions do not exist." We show this conclusion was reached on the basis of an…
The stress-energy tensor of a free quantized scalar field is calculated in the extreme Reissner-Nordstr\"{o}m black hole spacetime in the zero temperature vacuum state. The stress-energy appears to be regular on the event horizon, contrary…
We consider Reissner-Nordstrom solutions in quasi-topological gravity, obtaining exact solutions to the field equations yielding charged quasi-topological black holes. We study their thermodynamic behaviour over a range of parameters that…
The thermal view of scalar-tensor gravity is an analogy with a dissipative fluid. The scalar degree of freedom excites gravity to a positive ``temperature'', while Einstein gravity is the ``zero-temperature'' equilibrium state. We extend…
Recent results of quantum field theory on a curved spacetime suggest that extremal black holes are not thermal objects and that the notion of zero temperature is ill-defined for them. If this is correct, one may have to go to a full…
Constraints on the geometry of a static spherically symmetric black hole are obtained by requiring the spacetime curvature to be analytic at the event horizon. For a zero temperature black hole further constraints are obtained by also…
We study the possible existence of black holes in scalar-tensor theories of gravity in four dimensions. Their existence is verified for anomalous versions of these theories, with a negative kinetic term in the Lagrangian. The Hawking…
We review some properties of black hole structures appearing in gravity with a massless scalar field, with both minimal and nonminimal coupling. The main properties of the resulting cold black holes are described. The study of black holes…
We show that a gap exists in the allowed sizes of all zero temperature static spherically symmetric black holes in semiclassical gravity when only conformally invariant fields are present. The result holds for both charged and uncharged…