2,582 research outputs found
Surprises with angular momentum
The physics of angular momentum in even space dimensions can be surprisingly
counter-intuitive. Three such suprises, all associated with the properties of
supersymmetric rotating objects, are examined: (i) 5D black holes, (ii) Dyonic
instantons and (iii) Supertubes.Comment: 11 pp. Contribution to proceedings of TH-2002; revised to include
typographical corrections and further reference
Recurrent Acceleration in Dilaton-Axion Cosmology
A class of Einstein-dilaton-axion models is found for which almost all flat
expanding homogeneous and isotropic universes undergo recurrent periods of
acceleration. We also extend recent results on eternally accelerating open
universes.Comment: 8 pages, 7 figures. minor changes. Version 4 corrects a figure
captio
Anyons from Strings
The Nambu-Goto string in a 3-dimensional (3D) Minkowski spacetime is
quantized preserving Lorentz invariance and parity. The spectrum of massive
states contains anyons. An ambiguity in the ground state energy is resolved by
the 3D N=1 Green-Schwarz superstring, which has massless ground states
describing a dilaton and dilatino, and first-excited states of spin 1/4.Comment: 4 pages, two additional refs. in v
Supersymmetry of M-Branes at Angles
We determine the possible fractions of supersymmetry preserved by two
intersecting M-5-branes. These include the fractions 3/32 and 5/32 which have
not occurred previously in intersecting brane configurations. Both occur in
non-orthogonal pointlike intersections of M-5-branes but 5/32 supersymmetry is
possible only for specific fixed angles.Comment: 11 pages, Late
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