5,492 research outputs found
Stochastic integration in UMD Banach spaces
In this paper we construct a theory of stochastic integration of processes
with values in , where is a separable Hilbert space and
is a UMD Banach space (i.e., a space in which martingale differences are
unconditional). The integrator is an -cylindrical Brownian motion. Our
approach is based on a two-sided -decoupling inequality for UMD spaces due
to Garling, which is combined with the theory of stochastic integration of
-valued functions introduced recently by two of the authors.
We obtain various characterizations of the stochastic integral and prove
versions of the It\^{o} isometry, the Burkholder--Davis--Gundy inequalities,
and the representation theorem for Brownian martingales.Comment: Published at http://dx.doi.org/10.1214/009117906000001006 in the
Annals of Probability (http://www.imstat.org/aop/) by the Institute of
Mathematical Statistics (http://www.imstat.org
Stochastic evolution equations in UMD Banach spaces
We discuss existence, uniqueness, and space-time H\"older regularity for
solutions of the parabolic stochastic evolution equation dU(t) = (AU(t) +
F(t,U(t))) dt + B(t,U(t)) dW_H(t), t\in [0,\Tend], U(0) = u_0, where
generates an analytic -semigroup on a UMD Banach space and is a
cylindrical Brownian motion with values in a Hilbert space . We prove that
if the mappings and satisfy suitable Lipschitz conditions and is
\F_0-measurable and bounded, then this problem has a unique mild solution,
which has trajectories in C^\l([0,T];\D((-A)^\theta) provided
and satisfy \l+\theta<\frac12. Various extensions of this
result are given and the results are applied to parabolic stochastic partial
differential equations.Comment: Accepted for publication in Journal of Functional Analysi
Entropy Distance: New Quantum Phenomena
We study a curve of Gibbsian families of complex 3x3-matrices and point out
new features, absent in commutative finite-dimensional algebras: a
discontinuous maximum-entropy inference, a discontinuous entropy distance and
non-exposed faces of the mean value set. We analyze these problems from various
aspects including convex geometry, topology and information geometry. This
research is motivated by a theory of info-max principles, where we contribute
by computing first order optimality conditions of the entropy distance.Comment: 34 pages, 5 figure
Ito's formula in UMD Banach spaces and regularity of solutions of the Zakai equation
Using the theory of stochastic integration for processes with values in a UMD
Banach space developed recently by the authors, an Ito formula is proved which
is applied to prove the existence of strong solutions for a class of stochastic
evolution equations in UMD Banach spaces. The abstract results are applied to
prove regularity in space and time of the solutions of the Zakai equation.Comment: Accepted for publication in Journal of Differential Equation
Spin Coherence and N ESEEM Effects of Nitrogen-Vacancy Centers in Diamond with X-band Pulsed ESR
Pulsed ESR experiments are reported for ensembles of negatively-charged
nitrogen-vacancy centers (NV) in diamonds at X-band magnetic fields
(280-400 mT) and low temperatures (2-70 K). The NV centers in synthetic
type IIb diamonds (nitrogen impurity concentration ~ppm) are prepared with
bulk concentrations of cm to cm
by high-energy electron irradiation and subsequent annealing. We find that a
proper post-radiation anneal (1000C for 60 mins) is critically
important to repair the radiation damage and to recover long electron spin
coherence times for NVs. After the annealing, spin coherence times of T~ms at 5~K are achieved, being only limited by C nuclear spectral
diffusion in natural abundance diamonds. At X-band magnetic fields, strong
electron spin echo envelope modulation (ESEEM) is observed originating from the
central N nucleus. The ESEEM spectral analysis allows for accurate
determination of the N nuclear hypefine and quadrupole tensors. In
addition, the ESEEM effects from two proximal C sites (second-nearest
neighbor and fourth-nearest neighbor) are resolved and the respective C
hyperfine coupling constants are extracted.Comment: 10 pages, 5 figure
Finding a Mate With No Social Skills
Sexual reproductive behavior has a necessary social coordination component as
willing and capable partners must both be in the right place at the right time.
While there are many known social behavioral adaptations to support solutions
to this problem, we explore the possibility and likelihood of solutions that
rely only on non-social mechanisms. We find three kinds of social organization
that help solve this social coordination problem (herding, assortative mating,
and natal philopatry) emerge in populations of simulated agents with no social
mechanisms available to support these organizations. We conclude that the
non-social origins of these social organizations around sexual reproduction may
provide the environment for the development of social solutions to the same and
different problems.Comment: 8 pages, 5 figures, GECCO'1
Draft Genome Sequences of Campylobacter jejuni Strains That Cause Abortion in Livestock.
Campylobacter jejuni is an intestinal bacterium that can cause abortion in livestock. This publication announces the public release of 15 Campylobacter jejuni genome sequences from isolates linked to abortion in livestock. These isolates are part of the 100K Pathogen Genome Project and are from clinical cases at the University of California (UC) Davis
Draft Genome Sequence of Multidrug-Resistant Abortive Campylobacter jejuni from Northern California.
Campylobacter jejuni is an enteric bacterium that can cause abortion in livestock. This is the release of a multidrug-resistant Campylobacter jejuni genome from an isolate that caused an abortion in a cow in northern California. This isolate is part of the 100K Pathogen Genome Project
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