On compact perturbations of finite-zone Jacobi operators

2010 ◽  
Vol 165 (4) ◽  
pp. 473-482
Author(s):  
A. A. Kononova
2021 ◽  
Vol 382 (2) ◽  
pp. 657-707
Author(s):  
Marcus Webb ◽  
Sheehan Olver

AbstractWe address the computational spectral theory of Jacobi operators that are compact perturbations of the free Jacobi operator via the asymptotic properties of a connection coefficient matrix. In particular, for Jacobi operators that are finite-rank perturbations we show that the computation of the spectrum can be reduced to a polynomial root finding problem, from a polynomial that is derived explicitly from the entries of a connection coefficient matrix. A formula for the spectral measure of the operator is also derived explicitly from these entries. The analysis is extended to trace-class perturbations. We address issues of computability in the framework of the Solvability Complexity Index, proving that the spectrum of compact perturbations of the free Jacobi operator is computable in finite time with guaranteed error control in the Hausdorff metric on sets.


2003 ◽  
Vol 46 (3) ◽  
pp. 575-595 ◽  
Author(s):  
Jan Janas ◽  
Maria Malejki ◽  
Yaroslav Mykytyuk

AbstractIn this paper spectral properties of non-selfadjoint Jacobi operators $J$ which are compact perturbations of the operator $J_0=S+\rho S^*$, where $\rho\in(0,1)$ and $S$ is the unilateral shift operator in $\ell^2$, are studied. In the case where $J-J_0$ is in the trace class, Friedrichs’s ideas are used to prove similarity of $J$ to the rank one perturbation $T$ of $J_0$, i.e. $T=J_0+(\cdot,p)e_1$. Moreover, it is shown that the perturbation is of ‘smooth type’, i.e. $p\in\ell^2$ and$$ \varlimsup_{n\rightarrow\infty}|p(n)|^{1/n}\le\rho^{1/2}. $$When $J-J_0$ is not in the trace class, the Friedrichs method does not work and the transfer matrix approach is used. Finally, the point spectrum of a special class of Jacobi matrices (introduced by Atzmon and Sodin) is investigated.AMS 2000 Mathematics subject classification: Primary 47B36. Secondary 47B37


1977 ◽  
Vol 24 (1) ◽  
pp. 119-127 ◽  
Author(s):  
C. K. Chui ◽  
D. A. Legg ◽  
P. W. Smith ◽  
J. D. Ward

2021 ◽  
Vol 42 (5) ◽  
pp. 677-692
Author(s):  
Tingting Zhou ◽  
Bin Liang ◽  
Chaoyue Wang

Author(s):  
Domingo A. Herrero ◽  
Thomas J. Taylor ◽  
Zong Y. Wang

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