4 papers
Absolutely continuous spectrum of a Schrödinger operator on a tree
S. Kupin
We give sufficient conditions for the presence of the absolutely continuous spectrum of a Schrödinger operator on a regular rooted tree without loops (also called regular Bethe lat…
Lieb--Thirring bounds for complex Jacobi matrices
L. Golinskii, S. Kupin
We obtain various versions of classical Lieb--Thirring bounds for one- and multi-dimensional complex Jacobi matrices. Our method is based on Fan-Mirski Lemma and seems to be fairly…
Asymptotics of the orthogonal polynomials for the Szego class with a polynomial weight
S. Denisov, S. Kupin
Let p(t) be a trigonometric polynomial, non-negative on the unit circle. We say that a measure σbelongs to a polynomial Szego class, if the logarithm of its density is summable ove…
The Szego class with a polynomial weight
S. Denisov, S. Kupin
Let p be a trigonometric polynomial, nonnegative on the unit circle . We say that a measure on belongs to the polynomial Szego class, if $dσ=sigma'_{ac…