On weak and strong solution operators for evolution equations coming from quadratic operators

Alexandru Aleman (1) , Joe Viola (2)

1 Department of Mathematics [Lund University]
2 LMJL - Laboratoire de Mathématiques Jean Leray

We identify, through a change of variables, solution operators for evolution equations with generators given by certain simple first-order differential operators acting on Fock spaces. This analysis applies, through unitary equivalence, to a broad class of supersymmetric quadratic multiplication-differentiation operators acting on $L^2(\Bbb{R}^n)$ which includes the elliptic and weakly elliptic quadratic operators. We demonstrate a variety of sharp results on boundedness, decay, and return to equilibrium for these solution operators, connecting the short-time behavior with the range of the symbol and the long-time behavior with the eigenvalues of their generators. This is particularly striking when it allows for the definition of solution operators which are compact and regularizing for large times for certain operators whose spectrum is the entire complex plane.

Mots clés: Bargmann transform; Fock space; supersymmetric operator; quadratic operator; non-self-adjoint operator; evolution equation

Domaines: Equations aux dérivées partielles [math.AP]; Analyse fonctionnelle [math.FA]; Physique mathématique [math-ph]

Alexandru Aleman, Joe Viola. On weak and strong solution operators for evolution equations coming from quadratic operators. Journal of Spectral Theory, 2018, 8 (1), pp.33-121. ⟨10.4171/JST/191⟩. ⟨hal-01344692⟩