1,009 research outputs found
On perturbations of the isometric semigroup of shifts on the semiaxis
We study perturbations of the semigroup of shifts
on with the property that belongs to a certain Schatten-von Neumann class \gS_p with .
We show that, for the unitary component in the Wold-Kolmogorov decomposition of
the cogenerator of the semigroup , {\it any singular}
spectral type may be achieved by \gS_1 perturbations. We provide an explicit
construction for a perturbation with a given spectral type based on the theory
of model spaces of the Hardy space . Also we show that we may obtain {\it
any} prescribed spectral type for the unitary component of the perturbed
semigroup by a perturbation from the class \gS_p with
Использование золошлаковых материалов теплоэнергетики в строительных материалах
The possible trends to improve the building-technical properties of dry ashes characteristics formed as a result of solid fuel combustion at thermal power stations are presented. The results of different fly-ash conditioning technologies application to widen the trends and to increase the volumes of their use in the construction materials and products.Представлены возможные направления улучшения строительно-технических характеристик сухих зол, образующихся при сжигании твердого топлива на тепловых электростанциях. Приведены результаты применения различных технологий кондиционирования свойств золы для расширения направлений и увеличения объемов их использования при производстве строительных материалов и изделий
Nonperturbative Tests of Three-Dimensional Dualities
We test several conjectural dualities between strongly coupled superconformal
field theories in three dimensions by computing their exact partition functions
on a three-sphere as a function of Fayet-Iliopoulos and mass parameters. The
calculation is carried out using localization of the path integral and the
matrix model previously derived for superconformal N = 2 gauge theories. We
verify that the partition functions of quiver theories related by mirror
symmetry agree provided the mass parameters and the Fayet-Iliopoulos parameters
are exchanged, as predicted. We carry out a similar calculation for the mirror
of N = 8 super-Yang-Mills theory and show that its partition function agrees
with that of the ABJM theory at unit Chern-Simons level. This provides a
nonperturbative test of the conjectural equivalence of the two theories in the
conformal limit
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