21,569 research outputs found
Dyonic AdS black holes in maximal gauged supergravity
We present two new classes of dyonic anti-de Sitter black hole solutions of
4-dimensional maximal N=8, SO(8) gauged supergravity. They are: (1) static
black holes of N=2, U(1)^4 gauged supergravity with 4 electric and 4 magnetic
charges, with spherical, planar or hyperbolic horizons; and (2) rotating black
holes of N=2, U(1)^2 gauged supergravity with 2 electric and 2 magnetic
charges. We study their thermodynamics, and point out that the formulation of a
consistent thermodynamics for dyonic anti-de Sitter black holes is dependent on
the existence of boundary conditions for the gauge fields. We identify several
distinct classes of boundary conditions for gauge fields in U(1)^4
supergravity. We study a general family of metrics containing the rotating
solutions, and find Killing-Yano tensors with torsion in two conformal frames,
which underlie separability.Comment: 23 pages, 3 Mathematica files of solutions; v2: minor change
Quantum Coins, Dice and Children: Probability and Quantum Statistics
We discuss counterintuitive aspects of probabilities for systems of identical
particles obeying quantum statistics. Quantum coins and children (two level
systems) and quantum dice (many level systems) are used as examples. It is
emphasized that, even in the absence of interactions, (anti)symmetrizations of
multi-particle wavefunctions destroy statistical independences and often lead
to dramatic departures from our intuitive expectations.Comment: 8 pages in REVTe
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