1,011 research outputs found
Special limits and non-relativistic solutions
We study special vanishing horizon limit of `boosted' black D3-branes having
a compact light-cone direction. The type IIB solution obtained by taking such a
zero temperature limit is found to describe a nonrelativistic system with
dynamical exponent 3. We discuss about such limits in M2-branes case also.Comment: 10 pages; V2: various changes in interpretations including title; no
change in mathematical results, V3: minor font typo in eq.(7) remove
Finite Temperature Aging Holography
We construct the gravity background which describes the dual field theory
with aging invariance. We choose the decay modes of the bulk scalar field in
the internal spectator direction to obtain the dissipative behavior of the
boundary correlation functions of the dual scalar fields. In particular, the
two-time correlation function at zero temperature has the characteristic
features of the aging system: power law decay, broken time translation and
dynamical scaling. We also construct the black hole backgrounds with asymptotic
aging invariance. We extensively study characteristic behavior of the finite
temperature two-point correlation function via analytic and numerical methods.Comment: 38 pages and 5 figures, expanded discussions on correlator, one
mistake is fixed, modified discussion on shear viscosity, to appear in JHE
The Far-Infrared Properties of Spatially Resolved AKARI Observations
We present the spatially resolved observations of IRAS sources from the
Japanese infrared astronomy satellite AKARI All-Sky Survey during the
performance verification (PV) phase of the mission. We extracted reliable point
sources matched with IRAS point source catalogue. By comparing IRAS and AKARI
fluxes, we found that the flux measurements of some IRAS sources could have
been over or underestimated and affected by the local background rather than
the global background. We also found possible candidates for new AKARI sources
and confirmed that AKARI observations resolved IRAS sources into multiple
sources. All-Sky Survey observations are expected to verify the accuracies of
IRAS flux measurements and to find new extragalactic point sources.Comment: 11 pages, 7 figures, accepted publication in PASJ AKARI special issu
Holographic flows to IR Lifshitz spacetimes
Recently we studied `vanishing' horizon limits of `boosted' black D3-brane
geometry \cite{hsnr}. The type IIB solutions obtained by taking these special
double limits were found to describe nonrelativistic Lifshitz spacetimes at
zero temperature. In the present work we study these limits for TsT black-hole
solutions which include -field. The new Galilean solutions describe a
holographic RG flow from Schr\"odinger () spacetime in UV to a Lifshitz
universe () in the IR.Comment: 10 pages; v2: A bad typo in eq.8 corrected; v3: Discussion and
reference on Kaigorodov spaces included, correction in sec-3, to be published
in JHE
The particle number in Galilean holography
Recently, gravity duals for certain Galilean-invariant conformal field
theories have been constructed. In this paper, we point out that the spectrum
of the particle number operator in the examples found so far is not a necessary
consequence of the existence of a gravity dual. We record some progress towards
more realistic spectra. In particular, we construct bulk systems with
asymptotic Schrodinger symmetry and only one extra dimension. In examples, we
find solutions which describe these Schrodinger-symmetric systems at finite
density. A lift to M-theory is used to resolve a curvature singularity. As a
happy byproduct of this analysis, we realize a state which could be called a
holographic Mott insulator.Comment: 29 pages, 1 rudimentary figure; v2: typo in eqn (3.4), added comments
and ref
The mu problem and sneutrino inflation
We consider sneutrino inflation and post-inflation cosmology in the singlet
extension of the MSSM with approximate Peccei-Quinn(PQ) symmetry, assuming that
supersymmetry breaking is mediated by gauge interaction. The PQ symmetry is
broken by the intermediate-scale VEVs of two flaton fields, which are
determined by the interplay between radiative flaton soft masses and higher
order terms. Then, from the flaton VEVs, we obtain the correct mu term and the
right-handed(RH) neutrino masses for see-saw mechanism. We show that the RH
sneutrino with non-minimal gravity coupling drives inflation, thanks to the
same flaton coupling giving rise to the RH neutrino mass. After inflation,
extra vector-like states, that are responsible for the radiative breaking of
the PQ symmetry, results in thermal inflation with the flaton field, solving
the gravitino problem caused by high reheating temperature. Our model predicts
the spectral index to be n_s\simeq 0.96 due to the additional efoldings from
thermal inflation. We show that a right dark matter abundance comes from the
gravitino of 100 keV mass and a successful baryogenesis is possible via
Affleck-Dine leptogenesis.Comment: 27 pages, no figures, To appear in JHE
Lifshitz/Schr\"odinger D-p-branes and dynamical exponents
We extend our earlier study of special double limits of `boosted'
black hole solutions to include all black D-branes of type II strings. We
find that Lifshitz solutions can be obtained in generality, with varied
dynamical exponents, by employing these limits. We then study such double
limits for `boosted' D-brane bubble solutions and find that the resulting
non-relativistic solutions instead describe Schr\"odinger like spacetimes,
having varied dynamical exponents. We get a simple map between these Lifshitz &
Schr\"odinger solutions and a relationship between two types of dynamical
exponents. We also discuss about the singularities of the Lifshitz solutions
and an intriguing thermodynamic duality.Comment: 20 pages; 3 figures; v3: similar to JHE
Universal time-dependent deformations of Schrodinger geometry
We investigate universal time-dependent exact deformations of Schrodinger
geometry. We present 1) scale invariant but non-conformal deformation, 2)
non-conformal but scale invariant deformation, and 3) both scale and conformal
invariant deformation. All these solutions are universal in the sense that we
could embed them in any supergravity constructions of the Schrodinger invariant
geometry. We give a field theory interpretation of our time-dependent
solutions. In particular, we argue that any time-dependent chemical potential
can be treated exactly in our gravity dual approach.Comment: 24 pages, v2: references adde
Universality and exactness of Schrodinger geometries in string and M-theory
We propose an organizing principle for classifying and constructing
Schrodinger-invariant solutions within string theory and M-theory, based on the
idea that such solutions represent nonlinear completions of linearized vector
and graviton Kaluza-Klein excitations of AdS compactifications. A crucial
simplification, derived from the symmetry of AdS, is that the nonlinearities
appear only quadratically. Accordingly, every AdS vacuum admits infinite
families of Schrodinger deformations parameterized by the dynamical exponent z.
We exhibit the ease of finding these solutions by presenting three new
constructions: two from M5 branes, both wrapped and extended, and one from the
D1-D5 (and S-dual F1-NS5) system. From the boundary perspective, perturbing a
CFT by a null vector operator can lead to nonzero beta-functions for spin-2
operators; however, symmetry restricts them to be at most quadratic in
couplings. This point of view also allows us to easily prove nonrenormalization
theorems: for any Sch(z) solution of two-derivative supergravity constructed in
the above manner, z is uncorrected to all orders in higher derivative
corrections if the deforming KK mode lies in a short multiplet of an AdS
supergroup. Furthermore, we find infinite classes of 1/4 BPS solutions with
4-,5- and 7-dimensional Schrodinger symmetry that are exact.Comment: 31 pages, plus appendices; v2, minor corrections, added refs, slight
change in interpretation in section 2.3, new Schrodinger and Lifshitz
solutions included; v3, clarifications in sections 2 and 3 regarding
existence of solutions and multi-trace operator
Aging Logarithmic Conformal Field Theory : a holographic view
We consider logarithmic extensions of the correlation and response functions
of scalar operators for the systems with aging as well as Schr\"odinger
symmetry. Aging is known to be the simplest nonequilibrium phenomena, and its
physical significances can be understood by the two-time correlation and
response functions. Their logarithmic part is completely fixed by the bulk
geometry in terms of the conformal weight of the dual operator and the dual
particle number.
Motivated by recent experimental realizations of Kardar-Parisi-Zhang
universality class in growth phenomena and its subsequent theoretical extension
to aging, we investigate our two-time correlation functions out of equilibrium,
which show several qualitatively different behaviors depending on the
parameters in our theory. They exhibit either growing or aging, i.e. power-law
decaying, behaviors for the entire range of our scaling time. Surprisingly, for
some parameter ranges, they exhibit growing at early times as well as aging at
later times.Comment: 1+26 pages, 15 figure
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