4 papers
Generic failure of uniform separation in planar Dirichlet spectra
Vincent Boulard
Can a bounded planar domain have a simple Dirichlet spectrum with uniformly separated consecutive eigenvalues? Dimension two is critical: Weyl's law permits both uniform separation…
Optimal geometric barriers for weighted observability of heat semigroups on metric measure spaces
Vincent Boulard, Amaury Hayat, Emmanuel Trélat
Weighted integrated observability inequalities for heat equations usually involve a small-time factor of the form . We prove that this scale is not an artefact of Carlema…
Generic non-vanishing of Dirichlet eigenfunction averages and absence of symmetries
Vincent Boulard
We prove that, for a generic -domain (with , ) in the sense of Baire category for the Micheletti topology, every Dirichlet-Laplacian…
F-equivalence for parabolic systems and applications to the stabilization of nonlinear PDE
Vincent Boulard, Amaury Hayat
We consider the -equivalence problem for parabolic systems: under which conditions a control system, governed by a parabolic operator and a control operator , can be made…