5 citations · 15 across the 4 of their papers we have counts for
6 papers · 1 filter
Fractal upper bounds on the density of semiclassical resonances
J. Sjoestrand, M. Zworski
For semiclassical problems we establish upper bounds on the number of resonances in boxes of size along the real axis, in terms of the dimension of the set of trapped trajector…
Functional calculus for non-commuting operators with real spectra via an iterated Cauchy formula
Mats Andersson, Johannes Sjoestrand
We define a smooth functional calculus for a non-commuting tuple of (unbounded) operators on a Banach space with real spectra and resolvents with temperate growth, by means o…
Perturbations of selfadjoint operators with periodic classical flow
Johannes Sjoestrand
We consider non-selfadjoint perturbations of a self-adjoint -pseudodifferential operator in dimension 2. In the present work we treat the case when the classical flow of the unp…
Resonances associated to a closed hyperbolic trajectory in dimension 2
Johannes Sjoestrand
We consider resonances in the semi-classical limit, generated by a single closed hyperbolic orbit, for an operator on . We determine all such resonancess in a domain ind…
Bohr-Sommerfeld quantization condition for non-selfadjoint operators in dimension 2
A. Melin, J. Sjoestrand
For a class of non-selfadjoint h-pseudodifferential operators in dimension 2, we determine all eigenvalues in an h-independent domain in the complex plane and show that they are gi…
Determinants of pseudodifferential operators and complex deformations of phase space
A. Melin, J. Sjoestrand
Consider an h-pseudodifferential operator P, whose symbol extends holomorphically to a tubular neighborhood of the real phase space and converges sufficiently fast to 1, so that th…