Publications (58)
Positive Hausdorff dimensional spectrum for the critical almost Mathieu operator
Bernard Helffer, Qinghui Liu, Yanhui Qu +1
Pleijel's theorem for Schrödinger operators with radial potentials
Philippe Charron, Bernard Helffer, Thomas Hoffmann-Ostenhof
Semiclassical analysis of Schrödinger operators with magnetic wells
Bernard Helffer, Yuri A. Kordyukov
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
Spectral minimal partitions for a thin strip on a cylinder or a thin annulus like domain with Neumann condition
Bernard Helffer, Thomas Hoffmann-Ostenhof
Sharp trace asymptotics for a class of 2D-magnetic operators
Horia D. Cornean, Soren Fournais, Rupert Frank +1
Semiclassical reduction for magnetic Schroedinger operator with periodic zero-range potentials and applications
Bernard Helffer, Konstantin Pankrashkin
On the number of nodal domains of the 2D isotropic quantum harmonic oscillator -- an extension of results of A. Stern --
Pierre Bérard, Bernard Helffer
On a Schrödinger operator with a purely imaginary potential in the semiclassical limit
Yaniv Almog, Denis Grebenkov, Bernard Helffer
Semiclassical spectral asymptotics for a magnetic Schrödinger operator with non-vanishing magnetic field
Bernard Helffer, Yuri A. Kordyukov
Magnetic calculus and semiclassical trace formulas
Bernard Helffer, Radu Purice
Semiclassical spectral asymptotics for a two-dimensional magnetic Schrödinger operator II: The case of degenerate wells
Bernard Helffer, Yuri A. Kordyukov
Lower bound for the number of critical points of minimal spectral k-partitions for k large
Bernard Helffer
Semiclassical asymptotics and gaps in the spectra of periodic Schrödinger operators with magnetic wells
Bernard Helffer, Yuri A. Kordyukov
Minimal partitions for anisotropic tori
Bernard Helffer, Thomas Hoffmann-Ostenhof
Spectral semi-classical analysis of a complex Schrödinger operator in exterior domains
Yaniv Almog, Denis Grebenkov, Bernard Helffer
Global stability of the normal state of superconductors in the presence of a strong electric current
Yaniv Almog, Bernard Helffer
On semi-Classical Questions Related to Signal Analysis
Taous-Meriem Laleg-Kirati, Bernard Helffer
The periodic magnetic Schrödinger operators: spectral gaps and tunneling effect
Bernard Helffer, Yuri A. Kordyukov
The density of superconductivity in the bulk regime
Bernard Helffer, Ayman Kachmar
Dirichlet eigenfunctions on the cube, sharpening the Courant nodal inequality
Bernard Helffer, Rola Kiwan
Semiclassical spectral asymptotics for a two-dimensional magnetic Schrödinger operator: The case of discrete wells
Bernard Helffer, Yuri A. Kordyukov
From constant to non-degenerately vanishing magnetic fields in superconductivity
Bernard Helffer, Ayman Kachmar
Nodal domains, spectral minimal partitions, and their relation to Aharonov-Bohm operators
Virginie Bonnaillie-Noël, Bernard Helffer, Thomas Hoffmann-Ostenhof
Decay of superconductivity away from the magnetic zero set
Bernard Helffer, Ayman Kachmar
A review on large k minimal spectral k-partitions and Pleijel's Theorem
Bernard Helffer, Thomas Hoffmann-Ostenhof
Chambers's formula for the graphene and the Hou model with kagome periodicity and applications
Bernard Helffer, Philippe Kerdelhué, Jimena Royo-Letelier
Accurate semiclassical spectral asymptotics for a two-dimensional magnetic Schrödinger operator
Bernard Helffer, Yuri A. Kordyukov
Courant-sharp Robin eigenvalues for the square and other planar domains
Katie Gittins, Bernard Helffer
On the semi-classical analysis of the groundstate energy of the Dirichlet Pauli operator
Bernard Helffer, Mikael Persson Sundqvist
Spectral properties of higher order anharmonic oscillators
Bernard Helffer, Mikael Persson
Magnetic Wells in Dimension Three
Bernard Helffer, Yuri Kordyukov, Nicolas Raymond +1
Tunneling between corners for Robin Laplacians
Bernard Helffer, Konstantin Pankrashkin
On bifurcations from normal solutions for superconducting states
Bernard Helffer, Mathieu Dutour
Mixed normal-superconducting states in the presence of strong electric currents
Yaniv Almog, Bernard Helffer, Xing-Bin Pan
On mathematical models for Bose-Einstein condensates in optical lattices (expanded version)
Amandine Aftalion, Bernard Helffer
From resolvent bounds to semigroup bounds
Bernard Helffer, Johannes Sjoestrand
Spectral gaps for periodic Schrödinger operators with hypersurface magnetic wells
Bernard Helffer, Yuri A. Kordyukov
The Ginzburg-Landau functional with vanishing magnetic field
Bernard Helffer, Ayman Kachmar
Semiclassical analysis of a nonlinear eigenvalue problem and non analytic hypoellipticity
Bernard Helffer, Didier Robert, Xue Ping Wang
Courant-sharp Robin eigenvalues for the square -- the case with small Robin parameter--
Katie Gittins, Bernard Helffer
On the spectrum of non-selfadjoint Schrödinger operators with compact resolvent
Yaniv Almog, Bernard Helffer
On the semi-classical analysis of the groundstate energy of the Dirichlet Pauli operator III: Magnetic fields that change sign
Bernard Helffer, Hynek KovaÅÃk, Mikael P. Sundqvist
The spectrum of a Schrödinger operator in a wire-like domain with a purely imaginary degenerate potential in the semiclassical limit
Yaniv Almog, Bernard Helffer
On the semi-classical analysis of the groundstate energy of the Dirichlet Pauli operator in non-simply connected domains
Bernard Helffer, Mikael Persson Sundqvist
Low lying spectral gaps induced by slowly varying magnetic fields
Horia D. Cornean, Bernard Helffer, Radu Purice
Superconductivity between HC2 and HC3
Søren Fournais, Bernard Helffer, Mikael Persson
Nodal domains in the square---the Neumann case
Bernard Helffer, Mikael Persson Sundqvist
Non-Linear Eigenvalues and Analytic Hypoellipticity
Sagun Chanillo, Bernard Helffer, Ari Laptev
On nodal domains in Euclidean balls
Bernard Helffer, Mikael Persson Sundqvist
Eigenvalues for the Robin Laplacian in domains with variable curvature
Bernard Helffer, Ayman Kachmar
Eigenvalue estimates for a three-dimensional magnetic Schrödinger operator
Bernard Helffer, Yuri A. Kordyukov
Inequalities for the lowest magnetic Neumann eigenvalue
Soeren Fournais, Bernard Helffer
Tunneling for the Robin Laplacian in smooth planar domains
Bernard Helffer, Ayman Kachmar, Nicolas Raymond
On a magnetic characterization of spectral minimal partitions
Bernard Helffer, Thomas Hoffmann-Ostenhof
The density of superconductivity in domains with corners
Bernard Helffer, Ayman Kachmar
Subelliptic estimates for some systems of complex vector fields : quasihomogeneous case
Makhlouf Derridj, Bernard Helffer
Compactness of the solution operator to d-bar in weighted L^2 - spaces
Friedrich Haslinger, Bernard Helffer