5 citations · 35 across the 33 of their papers we have counts for
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On maximal multiplicities for Hamiltonians with separable variables
B. Helffer, T. Hoffmann-Ostenhof, P. Marquetand
For , we consider the collection of all the rows, for which, for , the row consists of an increasi…
On the stability of laminar flows between plates
Yaniv Almog, Bernard Helffer
Consider a two-dimensional laminar flow between two plates, so that , given by , where sa…
Thin domain limit and counterexamples to strong diamagnetism
Bernard Helffer, Ayman Kachmar
We study the magnetic Laplacian and the Ginzburg-Landau functional in a thin planar, smooth, tubular domain and with a uniform applied magnetic field. We provide counterexamples to…
Courant-sharp Robin eigenvalues for the square -- the case with small Robin parameter--
Katie Gittins, Bernard Helffer
This article is the continuation of our first work on the determination of the cases where there is equality in Courant's Nodal Domain theorem in the case of a Robin boundary condi…
On the multiplicity of the second eigenvalue of the Laplacian in non simply connected domains--with some numerics--
Bernard Helffer, Thomas Hoffmann-Ostenhof, François Jauberteau +1
We revisit an interesting example proposed by Maria Hoffmann-Ostenhof, the second author and Nikolai Nadirashvili of a bounded domain in R2 for which the second eigenvalue of the D…