1,880 research outputs found
Entropy of Pairs of Dual Attractors in 6D/7D
We study the attractor mechanism of dual pairs of black brane bounds in N=2
supergravity in six and seven dimensions. First, we consider the effective
potentials of the 6D and 7D black branes as well as their entropies. The
contribution coming from the SO(1,1) factor of the moduli spaces M_{6D} and
M_{7D} of these theories is carefully analyzed and it is used to motivate the
study of the dual black branes bounds; which in turn allow to fix the critical
value of the dilaton at horizon. The attractor eqs of the black branes and the
bound pairs are derived by combining the criticality conditions of the
corresponding effective potentials and the Lagrange multiplier method capturing
constraints eqs on the fields moduli.Comment: 55 pages, 2 figures, To appear in JHE
The initial conditions of the Universe and holography
We address the initial conditions for an expanding cosmology using the
holographic principle. For the case of a closed model, the old prescription of
Fishler and Susskind, that uses the particle horizon to encode the bulk degrees
of freedom, can be implemented for accelerated models with enough acceleration.
As a bonus we have singularity free bouncing models. The bound is saturated for
co-dimension one branes dominated universes.Comment: Talk presented at the XXVIII Spanish Relativity Meeting E.R.E. 2005,
Oviedo, September 6-10, 2005, to be published by AIP Conference Proceedings,
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