Abstract:
We consider a class of discrete Schrödinger operators on an infinite homogeneous rooted tree. Potentials for these operators are given by the coefficients of recurrence relations satisfied on a multidimensional lattice by multiple orthogonal polynomials. For operators on a binary tree with potentials generated by multiple orthogonal polynomials with respect to systems of measures supported on disjoint intervals (Angelesco systems) and for compact perturbations of such operators, we show that the essential spectrum is equal to the union of the intervals supporting the orthogonality measures.
The work of the first author (Sections 1 and 2) was supported the Russian Science Foundation under grant 19-71-30004. The work of the second and third authors (Section 3) was supported by the Moscow Center for Fundamental and Applied Mathematics (project no. 20-03-01). The second author was also supported by the National Science Foundation (grants DMS-1464479 and DMS-1764245) and by the Van Vleck Professorship Research Award. The third author was also supported by the Simons Foundation (grant CGM-354538).
Citation:
A. I. Aptekarev, S. A. Denisov, M. L. Yattselev, “Discrete Schrödinger Operator on a Tree, Angelesco Potentials, and Their Perturbations”, Analysis and mathematical physics, Collected papers. On the occasion of the 70th birthday of Professor Armen Glebovich Sergeev, Trudy Mat. Inst. Steklova, 311, Steklov Math. Inst., Moscow, 2020, 5–13; Proc. Steklov Inst. Math., 311 (2020), 1–9
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\by A.~I.~Aptekarev, S.~A.~Denisov, M.~L.~Yattselev
\paper Discrete Schr\"odinger Operator on a Tree, Angelesco Potentials, and Their Perturbations
\inbook Analysis and mathematical physics
\bookinfo Collected papers. On the occasion of the 70th birthday of Professor Armen Glebovich Sergeev
\serial Trudy Mat. Inst. Steklova
\yr 2020
\vol 311
\pages 5--13
\publ Steklov Math. Inst.
\publaddr Moscow
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\jour Proc. Steklov Inst. Math.
\yr 2020
\vol 311
\pages 1--9
\crossref{https://doi.org/10.1134/S0081543820060012}
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This publication is cited in the following 7 articles:
Evgeny L. Korotyaev, “The number of eigenvalues of discrete Hamiltonian periodic in time”, Journal of Mathematical Analysis and Applications, 2025, 129294
A. I. Aptekarev, “Weak and Strong Asymptotics of Orthogonal Polynomials with Varying Weight”, J Math Sci, 278:2 (2024), 211
V. G. Lysov, “Mnogourovnevye interpolyatsii dlya obobschennoi sistemy Nikishina na grafe-dereve”, Tr. MMO, 83, no. 2, MTsNMO, M., 2022, 345–361
V. G. Lysov, “Multilevel interpolations for the generalized Nikishin system on a tree graph”, Trans. Moscow Math. Soc., –
A. I. Aptekarev, V. G. Lysov, “Multilevel interpolation for Nikishin systems and boundedness of Jacobi matrices on binary trees”, Russian Math. Surveys, 76:4 (2021), 726–728
A. I. Aptekarev, “Slabye i silnye asimptotiki ortogonalnykh mnogochlenov c «peremennym» vesom”, Posvyaschaetsya 70-letiyu prezidenta RUDN V.M. Filippova, SMFN, 67, no. 3, Rossiiskii universitet druzhby narodov, M., 2021, 427–441
V. G. Lysov, “Mixed Type Hermite–Padé Approximants for a Nikishin System”, Proc. Steklov Inst. Math., 311 (2020), 199–213