14,024 research outputs found
Hardy inequality and Pohozaev identity for operators with boundary singularities: some applications
We consider the Schr\"{o}dinger operator A_\l:=-\D -\l/|x|^2, \l\in \rr,
when the singularity is located on the boundary of a smooth domain
\Omega\subset \rr^N,
The aim of this Note is two folded. Firstly, we justify the extension of the
classical Pohozaev identity for the Laplacian to this case. The problem we
address is very much related to Hardy-Poincar\'{e} inequalities with boundary
singularities. Secondly, the new Pohozaev identity allows to develop the
multiplier method for the wave and the Schr\"{o}dinger equations. In this way
we extend to the case of boundary singularities well known observability and
control properties for the classical wave and Schr\"{o}dinger equations when
the singularity is placed in the interior of the domain (Vanconstenoble and
Zuazua \cite{judith})
Computer algebra tools for Feynman integrals and related multi-sums
In perturbative calculations, e.g., in the setting of Quantum Chromodynamics
(QCD) one aims at the evaluation of Feynman integrals. Here one is often faced
with the problem to simplify multiple nested integrals or sums to expressions
in terms of indefinite nested integrals or sums. Furthermore, one seeks for
solutions of coupled systems of linear differential equations, that can be
represented in terms of indefinite nested sums (or integrals). In this article
we elaborate the main tools and the corresponding packages, that we have
developed and intensively used within the last 10 years in the course of our
QCD-calculations
Flow field prediction and analysis study for project RAM B3 Final report
Flow field properties in shock layer surrounding Ram B3 vehicl
- âŚ