Approximate determination of eigenvalues and eigenvectors of selfadjoint operators
Approximately Invariant Subspaces for Unbounded Linear Operators. II.
Approximation with Restricted Spectra.
Asymptotic Behaviour of the Solution of a Semilinear Parabolic Equation.
Bemerkungen über Tensorprodukte koerzitiver Hilbertraum-Operatoren.
Cesaro asymptotic equipartition of energy in the coupled case.
Chandrasekhar ansatz and the generalized total angular momentum operator for the Dirac equation in the Kerr-Newman metric.
Characterizations of nonnegative selfadjoint extensions.
Circular operators related to some quantum observables
Circular operators related to the operator of multiplication by a homomorphism of a locally compact abelian group and its restrictions are completely characterized. As particular cases descriptions of circular operators related to various quantum observables are given.
CLR-estimate revisited : Lieb's approach with non path integrals
Conditions for two self-adjoint operators to commute or to satisfy the Weyl relation.
Convergence in Dirichlet law of certain stochastic integrals.
Convergence Rates for intermediate problems.
Correct selfadjoint and positive extensions of nondensely defined minimal symmetric operators.
Correction to "Approximation with Restricted Spectra".
Cosine families of unbounded normal operators
Criterion of -criticality for one term -order difference operators
We investigate the criticality of the one term -order difference operators . We explicitly determine the recessive and the dominant system of solutions of the equation . Using their structure we prove a criticality criterion.
Description of the structure of singular spectrum for Friedrichs model operators near singular point.
Differentiable -functional calculus for certain sums of non-commuting operators
We consider a special class of sums of non-commuting positive operators on L²-spaces and derive a formula for their holomorphic semigroups. The formula enables us to give sufficient conditions for these operators to admit differentiable -functional calculus for 1 ≤ p ≤ ∞. Our results are in particular applicable to certain sub-Laplacians, Schrödinger operators and sums of even powers of vector fields on solvable Lie groups with exponential volume growth.
Dirac Operations with Strongly Singular Potentials. Distinguished Self-Adjoint Extensions Constructed with a Spectral Gap Theorem and Cut-Off-Potentials.