370 research outputs found
Hydrodynamic Vortices and their Gravity Duals
In this talk we review analytical and numerical studies of hydrodynamic
vortices in conformal fluids and their gravity duals. We present two
conclusions. First, (3+1)-dimensional turbulence is within the range of
validity of the AdS/hydrodynamics correspondence. Second, the local equilibrium
of the fluid is equivalent to the ultralocality of the holographic
correspondence, in the sense that the bulk data at a given point is determined,
to any given precision, by the boundary data at a single point together with a
fixed number of derivatives. With this criterion we see that the cores of hot
and slow (3+1)-dimensional conformal generalizations of Burgers vortices are
everywhere in local equilibrium and their gravity duals are thus easily found.
On the other hand local equilibrium breaks down in the core of singular
(2+1)-dimensional vortices, but the holographic correspondence with Einstein
gravity may be used to define the boundary field theory in the region in which
the hydrodynamic description fails.Comment: 6 pages, Padova Strings proceedings to appear in Fortschritte der
Physi
Spiked Monopoles
We introduce the spiked monopole, which is a 't Hooft-Polyakov monopole with
two charged scalar Higgs fields, of which one enjoys a quartic
self-interaction. The free Higgs field behaves as in a BPS monopole, reducing
the inter-monopole repulsion. The other Higgs has a spiked profile similar to a
non-BPS monopole. Using the methods from numerical relativity recently adapted
to the Yang-Mills-Higgs theory by Vachaspati, we simulate the interactions of
such monopoles. During the long lifetime of these simulations the individual
monopoles are stable. We find that they are always repulsive, with a small
repulsion only when the interaction Higgs VEV is proportionately small. We
briefly comment on implications for giant monopole dark matter models and on
supermassive black hole seeding by the spikes.Comment: 18 pages, 4 PDF figure
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