162 citations · 394 across the 33 of their papers we have counts for
Showing 2003 · math.SPShow all
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math.SP2003★ 9 cited
Elementary linear algebra for advanced spectral problems
J. Sjoestrand, M. Zworski
We discuss the general method of Grushin problems, closely related to Shur complements, Feshbach projections and effective Hamiltonians, and describe various appearances in spectra…
math.SP2003
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…
math.SP2003★ 5 cited
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…