Zobrazeno 1 - 10
of 139
pro vyhledávání: '"Makarov, Konstantin A."'
Given a symmetric operator $\dot A$ with deficiency indices $(1,1)$ and its self-adjoint extension $A$ in a Hilbert space $\mathcal{H}$, we construct a (unique) L-system with the main operator in $\mathcal{H}$ such that its impedance mapping coincide
Externí odkaz:
http://arxiv.org/abs/2306.06828
Publikováno v:
Complex Analysis and Operator Theory, vol. 16, 107 (2022)
We study L-systems whose main operators are extensions of one-dimensional half-line Schr\"odinger operators with deficiency indices $(1, 1)$, the Schr\"odinger L-systems. Introducing new concepts of an c-entropy and dissipation coefficient for an L-s
Externí odkaz:
http://arxiv.org/abs/2108.06567
Autor:
Grubišić, Luka, Kostrykin, Vadim, Makarov, Konstantin A., Schmitz, Stephan, Veselić, Krešimir
We obtain sufficient conditions that ensure block diagonalization (by a direct rotation) of sign-indefinite symmetric sesquilinear forms as well as the associated operators that are semi-bounded neither from below nor from above. In the semi-bounded
Externí odkaz:
http://arxiv.org/abs/1710.05105
Autor:
Grubišić, Luka, Kostrykin, Vadim, Makarov, Konstantin A., Schmitz, Stephan, Veselić, Krešimir
Publikováno v:
J. Spectr. Theory 9 (2019), no.4, 1431-1457
We show that the generalized Reynolds number (in fluid dynamics) introduced by Ladyzhenskaya is closely related to the rotation of the positive spectral subspace of the Stokes block-operator in the underlying Hilbert space. We also explicitly evaluat
Externí odkaz:
http://arxiv.org/abs/1708.00509
We study unimodular transformations of conservative $L$-systems. Classes $\sM^Q$, $\sM^Q_\kappa$, $\sM^{-1,Q}_\kappa$ that are impedance functions of the corresponding $L$-systems are introduced. A unique unimodular transformation of a given $L$-syst
Externí odkaz:
http://arxiv.org/abs/1608.08583
Publikováno v:
Integral Equations and Operator Theory, 85(3), 399-425, 2016
In this paper we discuss the problem of decomposition for unbounded $2\times 2$ operator matrices by a pair of complementary invariant graph subspaces. Under mild additional assumptions, we show that such a pair of subspaces decomposes the operator m
Externí odkaz:
http://arxiv.org/abs/1509.07984
We study the impedance functions of conservative L-systems with the unbounded main operators. In addition to the generalized Donoghue class $\sM_\kappa$ of Herglotz-Nevanlinna functions considered by the authors earlier, we introduce "inverse" genera
Externí odkaz:
http://arxiv.org/abs/1506.06627
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 pages
Comment: 15 pages
Externí odkaz:
http://arxiv.org/abs/1412.6633
Let $d$ be a probability distribution. Under certain mild conditions we show that $$ \lim_{x\to\infty}x\sum_{n=1}^\infty \frac{d^{*n}(x)}{n}=1,\qquad\text{where}\quad d^{*n}:=\underbrace{\,d*d*\cdots*d\,}_{n\text{ times}}. $$ For a compactly supporte
Externí odkaz:
http://arxiv.org/abs/1411.2009
The problem of block diagonalization for diagonally dominant symmetric block operator matrices with self-adjoint diagonal entries is considered. We show that a reasonable block diagonalization with respect to a reducing graph subspace requires a rela
Externí odkaz:
http://arxiv.org/abs/1307.6439