84 citations · 204 across the 21 of their papers we have counts for
21 papers
Hardy inequalities for large fermionic systems
Rupert L. Frank, Thomas Hoffmann-Ostenhof, Ari Laptev +1
Given with , we are interested in the large -behavior of the optimal constant in the Hardy inequality $\sum_{n=1}^N (-Δ_n)^s \geq κ_N \sum_{n<m} |X…
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 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…
Nodal domains, spectral minimal partitions, and their relation to Aharonov-Bohm operators
Virginie Bonnaillie-Noël, Bernard Helffer, Thomas Hoffmann-Ostenhof
This survey is a short version of a chapter written by the first two authors in the book [A. Henrot, editor. Shape optimization and spectral theory. Berlin: De Gruyter, 2017] (wher…
Pleijel's theorem for Schrödinger operators with radial potentials
Philippe Charron, Bernard Helffer, Thomas Hoffmann-Ostenhof
In 1956 . Pleijel gave his celebrated theorem showing that the inequality in Courant's theorem on the number of nodal domains is strict for large eigenvalues of the Laplacian. T…
On a magnetic characterization of spectral minimal partitions
Bernard Helffer, Thomas Hoffmann-Ostenhof
Given a bounded open set in (or in a Riemannian manifold) and a partition of by open sets , we consider the quantity where …