32,326 research outputs found
Holographic studies of Einsteinian cubic gravity
Einsteinian cubic gravity provides a holographic toy model of a
nonsupersymmetric CFT in three dimensions, analogous to the one defined by
Quasi-topological gravity in four. The theory admits explicit non-hairy AdS
black holes and allows for numerous exact calculations, fully nonperturbative
in the new coupling. We identify several entries of the AdS/CFT dictionary for
this theory, and study its thermodynamic phase space, finding interesting new
phenomena. We also analyze the dependence of R\'enyi entropies for disk regions
on universal quantities characterizing the CFT. In addition, we show that
is given by a non-analytic function of the ECG coupling, and that the
existence of positive-energy black holes strictly forbids violations of the KSS
bound. Along the way, we introduce a new method for evaluating Euclidean
on-shell actions for general higher-order gravities possessing second-order
linearized equations on AdS. Our generalized action involves the very
same Gibbons-Hawking boundary term and counterterms valid for Einstein gravity,
which now appear weighted by the universal charge controlling the
entanglement entropy across a spherical region in the CFT dual to the
corresponding higher-order theory.Comment: 59 pages, 7 figures, 1 table; v4: typos fixe
Period Estimation in Astronomical Time Series Using Slotted Correntropy
In this letter, we propose a method for period estimation in light curves
from periodic variable stars using correntropy. Light curves are astronomical
time series of stellar brightness over time, and are characterized as being
noisy and unevenly sampled. We propose to use slotted time lags in order to
estimate correntropy directly from irregularly sampled time series. A new
information theoretic metric is proposed for discriminating among the peaks of
the correntropy spectral density. The slotted correntropy method outperformed
slotted correlation, string length, VarTools (Lomb-Scargle periodogram and
Analysis of Variance), and SigSpec applications on a set of light curves drawn
from the MACHO survey
TASEP hydrodynamics using microscopic characteristics
The convergence of the totally asymmetric simple exclusion process to the
solution of the Burgers equation is a classical result. In his seminal 1981
paper, Herman Rost proved the convergence of the density fields and local
equilibrium when the limiting solution of the equation is a rarefaction fan. An
important tool of his proof is the subadditive ergodic theorem. We prove his
results by showing how second class particles transport the rarefaction-fan
solution, as characteristics do for the Burgers equation, avoiding
subadditivity. In the way we show laws of large numbers for tagged particles,
fluxes and second class particles, and simplify existing proofs in the shock
cases. The presentation is self contained.Comment: 20 pages, 13 figures. This version is accepted for publication in
Probability Surveys, February 20 201
Fleming-Viot selects the minimal quasi-stationary distribution: The Galton-Watson case
Consider N particles moving independently, each one according to a
subcritical continuous-time Galton-Watson process unless it hits 0, at which
time it jumps instantaneously to the position of one of the other particles
chosen uniformly at random. The resulting dynamics is called Fleming-Viot
process. We show that for each N there exists a unique invariant measure for
the Fleming-Viot process, and that its stationary empirical distribution
converges, as N goes to infinity, to the minimal quasi-stationary distribution
of the Galton-Watson process conditioned on non-extinction.Comment: 25 page
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