This is an unedited transscript of the handwritten notes of my talk at the Master Class.

Limiting absorption principle is justified for second-order selfadjoint elliptic operators in two-dimensional spaces.

the aim of this note is to study the submajorization inequalities for $tau$-measurable operators in a semi-finite von neumann algebra on a hilbert space with a normal faithful semi-finite trace $tau$. the submajorization inequalities generalize some results due to zhang, furuichi and lin, etc..

We extend to infinite dimensional separable Hilbert spaces the Schur convexity property 13 of eigenvalues of a symmetric matrix with real entries. Our framework includes both the case of linear, selfadjoint, compact operators, and that of linear selfadjoint operators 15 that can be approximated by operators of finite rank and having a countable family of eigenvalues. The abstract results of the...

We use elementary algebraic properties of left, right multiplication operators to prove some deep structural left $m$-invertible, $m$-isometric, $m$-selfadjoint and other related classes Banach space operators, often adding value extant results.

We prove a variant of Krein’s resolvent formula for self-adjoint extensions given by arbitrary boundary conditions. A parametrization of all such extensions is suggested with the help of two bounded operators instead of multivalued operators and selfadjoint linear relations.