88,338 research outputs found
Black branes in asymptotically Lifshitz spacetime and viscosity/entropy ratios in Horndeski gravity
We investigate black brane solutions in asymptotically Lifshitz spacetime in
3+1-dimensional Horndeski gravity, which admit a critical exponent fixed at
. The cosmological constant depends on as .
We compute the shear viscosity in the 2+1-dimensional dual boundary field
theory via holographic correspondence. We investigate the violation of the
bound for viscosity to entropy density ratio of at
.Comment: 7 pages, no figures, 1 table. Version published in EP
Braneworlds in Horndeski gravity
In this paper we address the issue of finding braneworld solutions in a
five-dimensional Horndeski gravity and the mechanism of gravity localization
into the brane via `almost massless modes' for suitable values of the Horndeski
parameters. We compute the corrections to the Newtonian potential and discuss
the limit where four-dimensional gravity is recovered.Comment: 14 pages, 6 figure
Quantum interference-induced stability of repulsively bound pairs of excitations
We study the dynamics of two types of pairs of excitations which are bound
despite their strong repulsive interaction. One corresponds to doubly occupied
sites in one-dimensional Bose-Hubbard systems, the so-called doublons. The
other is pairs of neighboring excited spins in anisotropic Heisenberg spin-1/2
chains. We investigate the possibility of decay of the bound pairs due to
resonant scattering by a defect or due to collisions of the pairs. We find that
the amplitudes of the corresponding transitions are very small. This is a
result of destructive quantum interference and explains the stability of the
bound pairs.Comment: 12 pages, 3 figure
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