3 citations · 5 across the 8 of their papers we have counts for
8 papers
A Combinatorial Formula for Recursive Operator Sequences and Applications
Raul E. Curto, Abderrazzak Ech-charyfy, Kaissar Idrissi +1
We study sequences of bounded operators \((T_n)_{n \ge 0}\) on a complex separable Hilbert space \(\mathcal{H}\) that satisfy a linear recurrence relation of the form $$ T_{n+r} =…
A Recursive approach to the matrix moment problem
R. Curto, A. Ech-charyfy, K. Idrissi +1
In this paper, we study the truncated matrix moment problem in one variable through recursive matrix extensions. We give necessary and sufficient conditions for a recursive matrix…
Square root problem and Subnormal Aluthge transforms
Hamza El Azhar, Abdelouahab Hanine, Kaissar Idrissi +1
For a non negative measure with atoms, we study the relation between the Square Root Problem of and the problem of subnormality of the Aluthge transform…
Jumping flatness and Aluthge transform of recursive weighted shifts
H. El Azhar, K. Idrissi, E. H. Zerouali
We devote this paper to Hamburger type weighted shifts. We give in particular an affirmative answer to a problem concerning subnormality of the Aluthge transform of Hamburger momen…
The quintic complex moment problem
Hamza El Azhar, Ayoub Harrat, Kaissar Idrissi +1
Let be a given complex-valued sequence. The truncated complex moment problem (TCMP in short) involves determining necessary and s…
A note on weak positive matrices, finite mass measures and hyponormal weighted shifts
H. El Azhar, K. Idrissi, E. H. Zerouali
We study the class of Hankel matrices for which the -block-matrices are positive semi-definite. We prove that a -block-matrix has non zero determinant if and…
Complex moment problem and recursive relations
Kaissar Idrissi, El Hassan Zerouali
We introduce a new strategy in solving the truncated complex moment problem. To this aim we investigate recursive doubly indexed sequences and their characteristic polynomials. A c…
The Multivariable moment problems and recursive relations
Kaissar Idrissi, El Hassan Zerouali
Let be a -dimensional multisequence. Curto and Fialkow, have shown that if the infinite moment matrix is fini…