21 research outputs found
Logarithmic Corrections to Schwarzschild and Other Non-extremal Black Hole Entropy in Different Dimensions
Euclidean gravity method has been successful in computing logarithmic
corrections to extremal black hole entropy in terms of low energy data, and
gives results in perfect agreement with the microscopic results in string
theory. Motivated by this success we apply Euclidean gravity to compute
logarithmic corrections to the entropy of various non-extremal black holes in
different dimensions, taking special care of integration over the zero modes
and keeping track of the ensemble in which the computation is done. These
results provide strong constraint on any ultraviolet completion of the theory
if the latter is able to give an independent computation of the entropy of
non-extremal black holes from microscopic description. For Schwarzschild black
holes in four space-time dimensions the macroscopic result seems to disagree
with the existing result in loop quantum gravity.Comment: LaTeX, 40 pages; corrected small typos and added reference
Heat Kernel Expansion and Extremal Kerr-Newmann Black Hole Entropy in Einstein-Maxwell Theory
We compute the second Seely-DeWitt coefficient of the kinetic operator of the
metric and gauge fields in Einstein-Maxwell theory in an arbitrary background
field configuration. We then use this result to compute the logarithmic
correction to the entropy of an extremal Kerr-Newmann black hole.Comment: 12 page
Stochastic backgrounds of relic gravitons: a theoretical appraisal
Stochastic backgrounds or relic gravitons, if ever detected, will constitute
a prima facie evidence of physical processes taking place during the earliest
stages of the evolution of the plasma. The essentials of the stochastic
backgrounds of relic gravitons are hereby introduced and reviewed. The pivotal
observables customarily employed to infer the properties of the relic gravitons
are discussed both in the framework of the CDM paradigm as well as in
neighboring contexts. The complementarity between experiments measuring the
polarization of the Cosmic Microwave Background (such as, for instance, WMAP,
Capmap, Quad, Cbi, just to mention a few) and wide band interferometers (e.g.
Virgo, Ligo, Geo, Tama) is emphasized. While the analysis of the microwave sky
strongly constrains the low-frequency tail of the relic graviton spectrum,
wide-band detectors are sensitive to much higher frequencies where the spectral
energy density depends chiefly upon the (poorly known) rate of
post-inflationary expansion.Comment: 94 pages, 32 figure
Non-perturbative corrections to the one-loop free energy induced by a massive scalar field on a stationary slowly varying in space gravitational background
Appraising digital records, or Swimming in treacherous shoals
This paper explores the application and appropriateness of the More Product, Less Process methodology (originally devised for dealing with paper record backlogs) to the digital sphere