Displaying 461 – 480 of 1119

Showing per page

Spectral gap for an unrestricted Kawasaki type dynamics

Gustavo Posta (2010)

ESAIM: Probability and Statistics

We give an accurate asymptotic estimate for the gap of the generator of a particular interacting particle system. The model we consider may be informally described as follows. A certain number of charged particles moves on the segment [1,L] according to a Markovian law. One unitary charge, positive or negative, jumps from a site k to another site k'=k+1 or k'=k-1 at a rate which depends on the charge at site k and at site k'. The total charge of the system is preserved by the dynamics, in...

Spectral gap lower bound for the one-dimensional fractional Schrödinger operator in the interval

Kamil Kaleta (2012)

Studia Mathematica

We prove a uniform lower bound for the difference λ₂ - λ₁ between the first two eigenvalues of the fractional Schrödinger operator ( - Δ ) α / 2 + V , α ∈ (1,2), with a symmetric single-well potential V in a bounded interval (a,b), which is related to the Feynman-Kac semigroup of the symmetric α-stable process killed upon leaving (a,b). “Uniform” means that the positive constant C α appearing in our estimate λ - λ C α ( b - a ) - α is independent of the potential V. In the general case of α ∈ (0,2), we also find a uniform lower bound for...

Spectral gaps and exponential integrability of hitting times for linear diffusions

Oleg Loukianov, Dasha Loukianova, Shiqi Song (2011)

Annales de l'I.H.P. Probabilités et statistiques

Let X be a regular continuous positively recurrent Markov process with state space ℝ, scale function S and speed measure m. For a∈ℝ denote Ba+=supx≥am(]x, +∞[)(S(x)−S(a)), Ba−=supx≤am(]−∞; x[)(S(a)−S(x)). It is well known that the finiteness of Ba± is equivalent to the existence of spectral gaps of generators associated with X. We show how these quantities appear independently in the study of the exponential moments of hitting times of X. Then we establish a very direct relation between exponential...

Spectral statistics for random Schrödinger operators in the localized regime

François Germinet, Frédéric Klopp (2014)

Journal of the European Mathematical Society

We study various statistics related to the eigenvalues and eigenfunctions of random Hamiltonians in the localized regime. Consider a random Hamiltonian at an energy E in the localized phase. Assume the density of states function is not too flat near E . Restrict it to some large cube Λ . Consider now I Λ , a small energy interval centered at E that asymptotically contains infintely many eigenvalues when the volume of the cube Λ grows to infinity. We prove that, with probability one in the large volume...

Spectrum of randomly sampled multivariate ARMA models

Amina Kadi (1998)

Kybernetika

The paper is devoted to the spectrum of multivariate randomly sampled autoregressive moving-average (ARMA) models. We determine precisely the spectrum numerator coefficients of the randomly sampled ARMA models. We give results when the non-zero poles of the initial ARMA model are simple. We first prove the results when the probability generating function of the random sampling law is injective, then we precise the results when it is not injective.

Speed of the Brownian loop on a manifold

Rémi Léandre (2006)

Banach Center Publications

We define the speed of the curved Brownian bridge as a white noise distribution operating on stochastic Chen integrals.

Splitting the conservation process into creation and annihilation parts

Nicolas Privault (1998)

Banach Center Publications

The aim of this paper is the study of a non-commutative decomposition of the conservation process in quantum stochastic calculus. The probabilistic interpretation of this decomposition uses time changes, in contrast to the spatial shifts used in the interpretation of the creation and annihilation operators on Fock space.

Currently displaying 461 – 480 of 1119