239 research outputs found
Spectral Stieltjes-Type Integration and Some Applications
This paper presents Stieltjes-type integration for operator-valued functions
with respect to spectral families. The relation between Riemann-Stieltjes
integrals associated with some classes of spectral families including, in
particular, those that arise in the context of the Stone representation theorem
for Banach spaces is established. The developed approach is applied to the
structural analysis of the operators commuting with a one-parameter
representation satisfying the Generalized Stone theorem.Comment: This paper has been withdrawn by the author. This paper has been
substantially rewritte
Multiple operator integrals and spectral shift
Multiple scalar integral representations for traces of operator derivatives
are obtained and applied in the proof of existence of the higher order spectral
shift functions.Comment: 18 pages, to appear in Illinois J. Mat
Trace formulas for tuples of commuting contractions
This paper extends the trace formulas of [5] with perturbations in normed
ideals of to multivariate functions of commuting contractions admitting
a dilation to commuting normal contractions.Comment: 20 pages; several corrections made, abstract improved, references
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About integrated invariance, arising at resonance of oscillations in some types non-conservative mechanical systems
For system of two ordinary differential equations of the second order
representing autonomous non-conservative holonomic mechanical system, in case
of dynamics such as one-frequency periodical oscillations, is found integrated
invariant of movement.Comment: LaTeX2e, 3 page
Asymptotic expansions for trace functionals
We obtain Taylor approximations for functionals
defined on the bounded self-adjoint operators, where is a self-adjoint
operator with compact resolvent and is a sufficiently nice scalar function,
relaxing assumptions on the operators made in [17], and derive estimates and
representations for the remainders of these approximations.Comment: 19 pages, J. Funct. Ana
About new quasilinear model of heat conduction with finite velocity of heat front movement
A new quasilinear mathematical model of heat conduction with finite velocity
of heat front movement is offered.Comment: LaTeX2.09, 3 pages, 1 figur
On single commutators in II_1-factors
We investigate the question of whether all elements of trace zero in a
II_1-factor are single commutators. We show that all nilpotent elements are
single commutators, as are all normal elements of trace zero whose spectral
distributions are discrete measures. Some other classes of examples are
considered.Comment: 10 pages. version 2 modifies somewhat the discussion of Tucci's
operators and corrects some minor mistakes. It will appear in Proc. Amer.
Math. Soc version 3 adds references and makes minor correction
Perturbation formulas for traces on normed ideals
We prove perturbation results for traces on normed ideals in semifinite von
Neumann algebra factors. This includes the case of Dixmier traces. In
particular, we establish existence of spectral shift measures with initial
operators being dissipative or bounded, and show that these measures can have
singular components in the case of Dixmier traces. We also establish a
linearization formula for a Dixmier trace applied to perturbed operator
functions, a result that does not typically hold for normal traces.Comment: 33 pages, typos corrected; to appear in Comm. Math. Phy
On a perturbation determinant for accumulative operators
For a purely imaginary sign-definite perturbation of a self-adjoint operator,
we obtain exponential representations for the perturbation determinant in both
upper and lower half-planes and derive respective trace formulas.Comment: 15 page
Higher order spectral shift for contractions
We derive strong estimates for Schatten norms of operator derivatives along
paths of contractions and apply them to prove existence of higher order
spectral shift functions for pairs of contractions.Comment: 28 page
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