112 research outputs found
Quantum corrected non-thermal radiation spectrum from the tunnelling mechanism
Tunnelling mechanism is today considered a popular and widely used method in
describing Hawking radiation. However, in relation to black hole (BH) emission,
this mechanism is mostly used to obtain the Hawking temperature by comparing
the probability of emission of an outgoing particle with the Boltzmann factor.
On the other hand, Banerjee and Majhi reformulated the tunnelling framework
deriving a black body spectrum through the density matrix for the outgoing
modes for both the Bose-Einstein distribution and the Fermi-Dirac distribution.
In contrast, Parikh and Wilczek introduced a correction term performing an
exact calculation of the action for a tunnelling spherically symmetric particle
and, as a result, the probability of emission of an outgoing particle
corresponds to a non-strictly thermal radiation spectrum. Recently, one of us
(C. Corda) introduced a BH effective state and was able to obtain a
non-strictly black body spectrum from the tunnelling mechanism corresponding to
the probability of emission of an outgoing particle found by Parikh and
Wilczek. The present work introduces the quantum corrected effective
temperature and the corresponding quantum corrected effective metric is written
using Hawking's periodicity arguments. Thus, we obtain further corrections to
the non-strictly thermal BH radiation spectrum as the final distributions take
into account both the BH dynamical geometry during the emission of the particle
and the quantum corrections to the semiclassical Hawking temperature.Comment: 9 pages, the results of arXiv:1305.4529 have been partially reviewed.
Final version accepted for publication in the Galaxies Special Issue
"Advances in Gravitational Research", Guest Editor Lorenzo Iori
Universal thermodynamics in different gravity theories: Modified entropy on the horizons
The paper deals with universal thermodynamics for FRW model of the universe
bounded by apparent (or event) horizon. Assuming Hawking temperature on the
horizon, the unified first law is examined on the horizon for different gravity
theories. The results show that equilibrium configuration is preserved with a
modification to Bekenstein entropy on the horizon
A Study of Universal Thermodynamics in Brane World Scenario
A study of Universal thermodynamics is done in the frame work of RSII brane
model and DGP brane scenario. The Universe is chosen as FRW model bounded by
apparent or event horizon. Assuming extended Hawking temperature on the
horizon, the unified first law is examined for perfect fluid (with constant
equation of state) and modified Chaplygin gas model. As a result there is a
modification of Bekenstein entropy on the horizons. Further the validity of the
generalized second law of thermodynamics and thermodynamical equilibrium are
also investigated
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