2,087 research outputs found
Holographic Butterfly Effect and Diffusion in Quantum Critical Region
We investigate the butterfly effect and charge diffusion near the quantum
phase transition in holographic approach. We argue that their criticality is
controlled by the holographic scaling geometry with deformations induced by a
relevant operator at finite temperature. Specifically, in the quantum critical
region controlled by a single fixed point, the butterfly velocity decreases
when deviating from the critical point. While, in the non-critical region, the
behavior of the butterfly velocity depends on the specific phase at low
temperature. Moreover, in the holographic Berezinskii-Kosterlitz-Thouless
transition, the universal behavior of the butterfly velocity is absent.
Finally, the tendency of our holographic results matches with the numerical
results of Bose-Hubbard model. A comparison between our result and that in the
nonlinear sigma model is also given.Comment: 41 pages, 7 figures, minor revisions, refs adde
Holographic Shear Viscosity in Hyperscaling Violating Theories without Translational Invariance
In this paper we investigate the ratio of shear viscosity to entropy density,
, in hyperscaling violating geometry with lattice structure. We show
that the scaling relation with hyperscaling violation gives a strong constraint
to the mass of graviton and usually leads to a power law of temperature,
. We find the exponent can be greater than two
such that the new bound for viscosity raised in arXiv:1601.02757 is violated.
Our above observation is testified by constructing specific solutions with UV
completion in various holographic models. Finally, we compare the boundedness
of with the behavior of entanglement entropy and conjecture a relation
between them.Comment: 38 pages, 8 figures: 1 appendix added, 2 figures added, 1 references
adde
Test of semi-local duality in a large framework
In this paper we test the semi-local duality based on the method of Ref.[1]
for calculating final-state interactions at varying number of colors ().
We compute the amplitudes by dispersion relations that respect analyticity and
coupled channel unitarity, as well as accurately describing experiment. The
dependence of the scattering amplitudes is obtained by
comparing these amplitudes to the one of chiral perturbation theory. The
semi-local duality is investigated by varying . Our results show that the
semi-local duality is not violated when is large. At large , the
contributions of the , the and the cancel
that of the in the finite energy sum rules, while the
has almost no effect. This gives further credit to the method developed in
Ref.[1] for investigating the dependence of hadron-hadron scattering with
final-state interactions. This study is also helpful to understand the
structure of the scalar mesons.Comment: 8 pages, 5 figures, several comments are adde
Maximal violation of Clauser-Horne-Shimony-Holt inequality for two qutrits
Bell-Clauser-Horne-Shimony-Holt inequality (in terms of correlation
functions) of two qutrits is studied in detail by employing tritter
measurements. A uniform formula for the maximum value of this inequality for
tritter measurements is obtained. Based on this formula, we show that
non-maximally entangled states violate the Bell-CHSH inequality more strongly
than the maximally entangled one. This result is consistent with what was
obtained by Ac{\'{i}}n {\it et al} [Phys. Rev. A {\bf 65}, 052325 (2002)] using
the Bell-Clauser-Horne inequality (in terms of probabilities).Comment: 6 pages, 3 figure
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