84 citations · 549 across the 98 of their papers we have counts for
27 papers · 1 filter
Stability of laminar monotone shear flows in a channel for high Reynolds number
Yaniv Almog, Bernard Helffer
We consider the stability of a laminar flow in the two-dimensional channel in the large Reynolds number limit. Assuming that is str…
On the stability of symmetric flows in a two-dimensional channel
Yaniv Almog, Bernard Helffer
We consider the stability of symmetric flows in a two-dimensional channel (including the Poiseuille flow). In 2015 Grenier, Guo, and Nguyen have established instability of these fl…
On critical points of eigenvalues of the Montgomery family of quartic oscillators
Bernard Helffer, Matthieu Léautaud
We discuss spectral properties of the family of quartic oscillators on the real line, where $α\in…
Upper bounds on eigenvalue multiplicities for spheres and plane domains revisited
Pierre Bérard, Bernard Helffer
We revisit two papers which appeared in 1999: M.~Hoffmann-Ostenhof, T.~Hoffmann-Ostenhof, and N.~Nadirashvili [Ann. Global Anal. Geom. 17 (1999) 43--48] and T.~Hoff\-mann-Ostenhof,…
Exponential localization of Steklov eigenfunctions on warped product manifolds: the flea on the elephant phenomenon
Thierry Daudé, Bernard Helffer, François Nicoleau
This paper is devoted to the analysis of Steklov eigenvalues and Steklov eigenfunctions on a class of warped product Riemannian manifolds whose boundary consis…
Maximal estimates for the Kramers-Fokker-Planck operator with electromagnetic field
Bernard Helffer, Zeinab Karaki
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 o…