Tunnel effect and symmetries for Kramers Fokker-Planck type operators

具有长程势的Kramers-Fokker-Planck算子的谱性质

Spectral properties of the Kramers-Fokker-Planck operator with a long-range potential

本文研究带长程势的Kramers-Fokker-Planck算子的谱性质，证明阈值是特征值唯一可能的聚点、例外集外极限吸收原理成立，并刻画了离散与嵌入非阈值特征值对应特征函数的不同衰减速率。

Tunnel effect for Kramers-Fokker-Planck type operators

We consider operators of Kramers-Fokker-Planck type in the semi-classical limit such that the exponent of the associated Maxwellian is a Morse function with two local minima and a saddle point. Under suitable additional assumptions we establish the complete asymptotics of the exponentially small splitting between the first two eigenvalues.

Semiclassical analysis for the Kramers-Fokker-Planck equation

We study some accurate semiclassical resolvent estimates for operators that are neither selfadjoint nor elliptic, and applications to the Cauchy problem. In particular we get a precise description of the spectrum near the imaginary axis and precise resolvent estimates inside the pseudo-spectrum. We apply our results to the Kramers-Fokker-Planck operator.

On the Kramers-Fokker-Planck equation with decreasing potentials in dimension one

For quickly decreasing potentials with one position variable, the first threshold zero is always a resonance of the Kramers-Fokker-Planck operator. In this article we study low-energy spectral properties of the operator and calculate large time asymptotics of solutions in terms of the Maxwellian.

Maximal estimates for the Kramers-Fokker-Planck operator with electromagnetic field

In continuation of a former work by the first author with F. Nier (2009) and of a more recent work by the second author on the torus (2019), we consider the Kramers-Fokker-Planck operator (KFP) with an external electromagnetic field on R d. We show a maximal type estimate on this operator using a nilpotent approach for vector field polynomial operators and induced representations of a nilpotent graded Lie algebra. This estimate leads to an optimal characterization of the domain of the closure of the KFP operator and a criterion for the compactness of the resolvent.

Large-time asymptotics of solutions to the Kramers-Fokker-Planck equation with a short-range potential

In this work, we use scattering method to study the Kramers-Fokker-Planck equation with a potential whose gradient tends to zero at the infinity. For short-range potentials in dimension three, we show that complex eigenvalues do not accumulate at low-energies and establish the low-energy resolvent asymptotics. This combined with high energy pseudospectral estimates valid in more general situations gives the large-time asymptotics of the solution in weighted $L^2$ spaces.