The name “Grushin problem” refers here to the variation of Schur complement
technique introduced by J. Sjöstrand in his early works, which is now a commonly
used tool in spectral analysis (see
Acta. Math.130 (1973), 1–51 and
Ann. Inst.Fourier57:7 (2007), 2095–2141). Recently Q. Ren and Z. Tao proposed
such an approach for the analysis of the low-lying eigenvalues in the large
friction limit for a simple scalar kinetic model. Inspired by this work and
the introduction of functional spaces adapted to the analysis of geometric
Kramers–Fokker–Planck operators in a previous article, here we study the combined
asymptotic analysis of Bismut’s hypoelliptic Laplacian in the high friction
and possibly low
temperature
regimes.
Keywords
Bismut's hypoelliptic Laplacian, Grushin problem, spectral
convergence, multiscale analysis, large friction, low
temperature