14,962 research outputs found
Bernoulli polynomials and Pascal matrices in the context of Clifford analysis
AbstractThis paper describes an approach to generalized Bernoulli polynomials in higher dimensions by using Clifford algebras. Due to the fact that the obtained Bernoulli polynomials are special hypercomplex holomorphic (monogenic) functions in the sense of Clifford Analysis, they have properties very similar to those of the classical polynomials. Hypercomplex Pascal and Bernoulli matrices are defined and studied, thereby generalizing results recently obtained by Zhang and Wang (Z. Zhang, J. Wang, Bernoulli matrix and its algebraic properties, Discrete Appl. Math. 154 (11) (2006) 1622–1632)
On the modulus of continuity for spectral measures in substitution dynamics
The paper gives first quantitative estimates on the modulus of continuity of
the spectral measure for weak mixing suspension flows over substitution
automorphisms, which yield information about the "fractal" structure of these
measures. The main results are, first, a Hoelder estimate for the spectral
measure of almost all suspension flows with a piecewise constant roof function;
second, a log-Hoelder estimate for self-similar suspension flows; and, third, a
Hoelder asymptotic expansion of the spectral measure at zero for such flows.
Our second result implies log-Hoelder estimates for the spectral measures of
translation flows along stable foliations of pseudo-Anosov automorphisms. A key
technical tool in the proof of the second result is an "arithmetic-Diophantine"
proposition, which has other applications. In the appendix this proposition is
used to derive new decay estimates for the Fourier transforms of Bernoulli
convolutions.Comment: 42 pages, accepted version; to appear in Advances in Mathematic
Extended Bernoulli and Stirling matrices and related combinatorial identities
In this paper we establish plenty of number theoretic and combinatoric
identities involving generalized Bernoulli and Stirling numbers of both kinds.
These formulas are deduced from Pascal type matrix representations of Bernoulli
and Stirling numbers. For this we define and factorize a modified Pascal matrix
corresponding to Bernoulli and Stirling cases.Comment: Accepted for publication in Linear Algebra and its Application
Identifiability of parameters in latent structure models with many observed variables
While hidden class models of various types arise in many statistical
applications, it is often difficult to establish the identifiability of their
parameters. Focusing on models in which there is some structure of independence
of some of the observed variables conditioned on hidden ones, we demonstrate a
general approach for establishing identifiability utilizing algebraic
arguments. A theorem of J. Kruskal for a simple latent-class model with finite
state space lies at the core of our results, though we apply it to a diverse
set of models. These include mixtures of both finite and nonparametric product
distributions, hidden Markov models and random graph mixture models, and lead
to a number of new results and improvements to old ones. In the parametric
setting, this approach indicates that for such models, the classical definition
of identifiability is typically too strong. Instead generic identifiability
holds, which implies that the set of nonidentifiable parameters has measure
zero, so that parameter inference is still meaningful. In particular, this
sheds light on the properties of finite mixtures of Bernoulli products, which
have been used for decades despite being known to have nonidentifiable
parameters. In the nonparametric setting, we again obtain identifiability only
when certain restrictions are placed on the distributions that are mixed, but
we explicitly describe the conditions.Comment: Published in at http://dx.doi.org/10.1214/09-AOS689 the Annals of
Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical
Statistics (http://www.imstat.org
Information-theoretical meaning of quantum dynamical entropy
The theory of noncommutative dynamical entropy and quantum symbolic dynamics
for quantum dynamical systems is analised from the point of view of quantum
information theory. Using a general quantum dynamical system as a communication
channel one can define different classical capacities depending on the
character of resources applied for encoding and decoding procedures and on the
type of information sources. It is shown that for Bernoulli sources the
entanglement-assisted classical capacity, which is the largest one, is bounded
from above by the quantum dynamical entropy defined in terms of operational
partitions of unity. Stronger results are proved for the particular class of
quantum dynamical systems -- quantum Bernoulli shifts. Different classical
capacities are exactly computed and the entanglement-assisted one is equal to
the dynamical entropy in this case.Comment: 6 page
Arithmetic Dynamics
This survey paper is aimed to describe a relatively new branch of symbolic
dynamics which we call Arithmetic Dynamics. It deals with explicit arithmetic
expansions of reals and vectors that have a "dynamical" sense. This means
precisely that they (semi-) conjugate a given continuous (or
measure-preserving) dynamical system and a symbolic one. The classes of
dynamical systems and their codings considered in the paper involve: (1)
Beta-expansions, i.e., the radix expansions in non-integer bases; (2)
"Rotational" expansions which arise in the problem of encoding of irrational
rotations of the circle; (3) Toral expansions which naturally appear in
arithmetic symbolic codings of algebraic toral automorphisms (mostly
hyperbolic).
We study ergodic-theoretic and probabilistic properties of these expansions
and their applications. Besides, in some cases we create "redundant"
representations (those whose space of "digits" is a priori larger than
necessary) and study their combinatorics.Comment: 45 pages in Latex + 3 figures in ep
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