Precise Asymptotics of Small Eigenvalues of Reversible Diffusions in the Metastable Regime
نویسندگان
چکیده
We investigate the close connection between metastability of the reversible diffusion process X defined by the stochastic differential equation dXt =−∇F (Xt)dt+ √ 2εdWt, ε > 0, and the spectrum near zero of its generator −Lε ≡ ε∆−∇F ·∇, where F :R → R and W denotes Brownian motion on R. For generic F to each local minimum of F there corresponds a metastable state. We prove that the distribution of its rescaled relaxation time converges to the exponential distribution as ε ↓ 0 with optimal and uniform error estimates. Each metastable state can be viewed as an eigenstate of Lε with eigenvalue which converges to zero exponentially fast in 1/ε. Modulo errors of exponentially small order in 1/ε this eigenvalue is given as the inverse of the expected metastable relaxation time. The eigenstate is highly concentrated in the basin of attraction of the corresponding trap.
منابع مشابه
Metastability in Reversible Diffusion Processes Ii. Precise Asymptotics for Small Eigenvalues
متن کامل
Marginal density expansions for diffusions and stochastic volatility, part II: Applications
In [17] we discussed density expansions for multidimensional diffusions ( X, . . . , X ) , at fixed time T and projected to their first l coordinates, in the small noise regime. Global conditions were found which replace the well-known ”not-in-cutlocus” condition known from heat-kernel asymptotics. In the present paper we discuss financial applications; these include tail and implied volatility...
متن کامل2 01 5 Varadhan ’ s formula , conditioned diffusions , and local volatilities
Motivated by marginals-mimicking results for Itô processes [15, 21] via SDEs and by their applications to volatility modeling in finance, we discuss the weak convergence of the law of a hypoelliptic diffusions conditioned to belong to a target affine subspace at final time, namely L(Zt|Yt = y) if X· = (Y·, Z·). To do so, we revisit Varadhan-type estimates in a small-noise regime, studying the d...
متن کاملLocalization of Eigenvalues in Small Specified Regions of Complex Plane by State Feedback Matrix
This paper is concerned with the problem of designing discrete-time control systems with closed-loop eigenvalues in a prescribed region of stability. First, we obtain a state feedback matrix which assigns all the eigenvalues to zero, and then by elementary similarity operations we find a state feedback which assigns the eigenvalues inside a circle with center and radius. This new algorithm ca...
متن کاملSpectral asymptotics of the Dirichlet Laplacian in a conical layer
The spectrum of the Dirichlet Laplacian on conical layers is analysed through two aspects: the infiniteness of the discrete eigenvalues and their expansions in the small aperture limit. On the one hand, we prove that, for any aperture, the eigenvalues accumulate below the threshold of the essential spectrum: For a small distance from the essential spectrum, the number of eigenvalues farther fro...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2005