5,792 research outputs found
Convergence of three-dimensional loop-erased random walk in the natural parametrization
In this work, we consider loop-erased random walk (LERW) and its scaling
limit in three dimensions, and prove that 3D LERW parametrized by renormalized
length converges to its scaling limit parametrized by some suitable measure
with respect to the uniform convergence topology in the lattice size scaling
limit. Our result improves the previous work of Gady Kozma (Acta Math.
199(1):29-152), which shows that the rescaled trace of 3D LERW converges weakly
to a random compact set with respect to the Hausdorff distance.Comment: 74 pages, 3 figure
Asymptotic minimax risk of predictive density estimation for non-parametric regression
We consider the problem of estimating the predictive density of future
observations from a non-parametric regression model. The density estimators are
evaluated under Kullback--Leibler divergence and our focus is on establishing
the exact asymptotics of minimax risk in the case of Gaussian errors. We derive
the convergence rate and constant for minimax risk among Bayesian predictive
densities under Gaussian priors and we show that this minimax risk is
asymptotically equivalent to that among all density estimators.Comment: Published in at http://dx.doi.org/10.3150/09-BEJ222 the Bernoulli
(http://isi.cbs.nl/bernoulli/) by the International Statistical
Institute/Bernoulli Society (http://isi.cbs.nl/BS/bshome.htm
Higher Rank Wilson Loops in N = 2* Super-Yang-Mills Theory
The N=2* Super-Yang-Mills theory (SYM*) undergoes an infinite sequence of
large-N quantum phase transitions. We compute expectation values of Wilson
loops in k-symmetric and antisymmetric representations of the SU(N) gauge group
in this theory and show that the same phenomenon that causes the phase
transitions at finite coupling leads to a non-analytic dependence of Wilson
loops on k/N when the coupling is strictly infinite, thus making the
higher-representation Wilson loops ideal holographic probes of the non-trivial
phase structure of SYM*.Comment: 33 pages, 6 figures. v2: a new reference adde
A prediction of neutrino mixing matrix with CP violating phase
The latest experimental progress have established three kinds of neutrino
oscillations with three mixing angles measured to rather high precision. There
is still one parameter, i.e., the CP violating phase, missing in the neutrino
mixing matrix. It is shown that a replay between different parametrizations of
the mixing matrix can determine the full neutrino mixing matrix together with
the CP violating phase. From the maximal CP violation observed in the original
Kobayashi-Maskawa (KM) scheme of quark mixing matrix, we make an Ansatz of
maximal CP violation in the neutrino mixing matrix. This leads to the
prediction of all nine elements of the neutrino mixing matrix and also a
remarkable prediction of the CP violating phase within
range from available experimental information. We also predict the three angles
of the unitarity triangle corresponding to the quark sector for confronting
with the CP-violation related measurements.Comment: 9 pages. Version accepted for publication in PLB, with methods for
CP-violating phase measurements discusse
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