Hawking Radiation for Non-minimally Coupled Matter from Generalized 2D Black Hole Models
نویسندگان
چکیده
It is well known that spherically symmetric reduction of General Relativity (SSG) leads to non-minimally coupled scalar matter. We generalize (and correct) recent results to Hawking radiation for a class of dilaton models which share with the Schwarzschild black hole nonminimal coupling of scalar fields and the basic global structure. An inherent ambiguity of such models (if they differ from SSG) is discussed. However, for SSG we obtain the rather disquieting result of a negative Hawking flux at infinity, if the usual recipe for such calculations is applied. e-mail: [email protected] e-mail: [email protected] e-mail: [email protected]
منابع مشابه
Non - minimal coupling , boundary terms and renormalization of the Einstein - Hilbert action and black hole entropy
A consistent variational procedure applied to the gravitational action requires according to Gibbons and Hawking a certain balance between the volume and boundary parts of the action. We consider the problem of preserving this balance in the quantum effective action for the matter non-minimally coupled to metric. It is shown that one has to add a special boundary term to the matter action analo...
متن کامل4D and 2D Evaporating Dilatonic Black Holes
The picture of S-wave scattering from a 4D extremal dilatonic black hole is examined. Classically, a small matter shock wave will form a non-extremal black hole. In the “throat region” the r − t geometry is exactly that of a collapsing 2D black hole. The 4D Hawking radiation (in this classical background) gives the 2D Hawking radiation exactly in the throat region. Inclusion of the back-reactio...
متن کاملHawking radiation and unitary evolution.
We find a family of exact solutions to the semi-classical equations (including back-reaction) of two-dimensional dilaton gravity, describing infalling null matter that becomes outgoing and returns to infinity without forming a black hole. When a black hole almost forms, the radiation reaching infinity in advance of the original outgoing null matter has the properties of Hawking radiation. The r...
متن کاملConformal Equivalence of 2d Dilaton Gravity Models
We investigate the behavior of generic, matter-coupled, 2D dilaton gravity theories under dilaton-dependent Weyl rescalings of the metric. We show that physical observables associated with 2D black holes, such as the mass, the temperature and the flux of Hawking radiation are invariant under the action of both Weyl transformations and dilaton reparametrizations. The field theoretical and geomet...
متن کاملRange of Validity of the D-Brane - Black Hole Correspondence
For minimally coupled scalars at low frequencies, the D-brane model has the same spectrum of radiation as the Hawking radiation from a black hole. We perform a similar comparison for another type of scalar which we call an intermediate scalar. In this case, we find that there is a discrepancy between the D-brane model and the black hole even for very low frequency scalars. This suggests that th...
متن کامل