Asymptotic expansion of the invariant measurefor Markov-modulated ODEs at high frequency

Fuente: arXiv
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Main Authors: Monmarché, Pierre, Strickler, Edouard
Format: Preprint
Published: 2023
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author Monmarché, Pierre
Strickler, Edouard
author_facet Monmarché, Pierre
Strickler, Edouard
contents We consider time-inhomogeneous ODEs whose parameters are governed by an underlying ergodic Markov process. When this underlying process is accelerated by a factor $\varepsilon^{-1}$, an averaging phenomenon occurs and the solution of the ODE converges to a deterministic ODE as $\varepsilon$ vanishes. We are interested in cases where this averaged flow is globally attracted to a point. In that case, the equilibrium distribution of the solution of the ODE converges to a Dirac mass at this point. We prove an asymptotic expansion in terms of $\varepsilon$ for this convergence, with a somewhat explicit formula for the first order term. The results are applied in three contexts: linear Markov-modulated ODEs, randomized splitting schemes, and Lotka-Volterra models in random environment. In particular, as a corollary, we prove the existence of two matrices whose convex combinations are all stable but such that, for a suitable jump rate, the top Lyapunov exponent of a Markov-modulated linear ODE switching between these two matrices is positive.
format Preprint
id arxiv_https___arxiv_org_abs_2309_16464
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Asymptotic expansion of the invariant measurefor Markov-modulated ODEs at high frequency
Monmarché, Pierre
Strickler, Edouard
Probability
Dynamical Systems
We consider time-inhomogeneous ODEs whose parameters are governed by an underlying ergodic Markov process. When this underlying process is accelerated by a factor $\varepsilon^{-1}$, an averaging phenomenon occurs and the solution of the ODE converges to a deterministic ODE as $\varepsilon$ vanishes. We are interested in cases where this averaged flow is globally attracted to a point. In that case, the equilibrium distribution of the solution of the ODE converges to a Dirac mass at this point. We prove an asymptotic expansion in terms of $\varepsilon$ for this convergence, with a somewhat explicit formula for the first order term. The results are applied in three contexts: linear Markov-modulated ODEs, randomized splitting schemes, and Lotka-Volterra models in random environment. In particular, as a corollary, we prove the existence of two matrices whose convex combinations are all stable but such that, for a suitable jump rate, the top Lyapunov exponent of a Markov-modulated linear ODE switching between these two matrices is positive.
title Asymptotic expansion of the invariant measurefor Markov-modulated ODEs at high frequency
topic Probability
Dynamical Systems
url https://arxiv.org/abs/2309.16464