106 research outputs found
On the Schatten-von Neumann properties of some pseudo-differential operators
We obtain a number of explicit estimates for quasi-norms of
pseudo-differential operators in the Schatten-von Neumann classes with
. The estimates are applied to derive semi-classical bounds for
operators with smooth or non-smooth symbols.Comment: 22 page
Decompositions of Gelfand-Shilov kernels into kernels of similar class
We prove that any linear operator with kernel in a Gelfand-Shilov space is a
composition of two operators with kernels in the same Gelfand-Shilov space. We
also give links on numerical approximations for such compositions. We apply
these composition rules to establish Schatten-von Neumann properties for such
operators.Comment: 13 pages. arXiv admin note: text overlap with arXiv:1102.033
A remark on Schatten-von Neumann properties of resolvent differences of generalized Robin Laplacians on bounded domains
In this note we investigate the asymptotic behaviour of the -numbers of
the resolvent difference of two generalized self-adjoint, maximal dissipative
or maximal accumulative Robin Laplacians on a bounded domain with
smooth boundary . For this we apply the recently introduced
abstract notion of quasi boundary triples and Weyl functions from extension
theory of symmetric operators together with Krein type resolvent formulae and
well-known eigenvalue asymptotics of the Laplace-Beltrami operator on
. It will be shown that the resolvent difference of two
generalized Robin Laplacians belongs to the Schatten-von Neumann class of any
order for which . Moreover, we also give a simple
sufficient condition for the resolvent difference of two generalized Robin
Laplacians to belong to a Schatten-von Neumann class of arbitrary small order.
Our results extend and complement classical theorems due to M.Sh.Birman on
Schatten-von Neumann properties of the resolvent differences of Dirichlet,
Neumann and self-adjoint Robin Laplacians
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