Spectral Multiplicity Bounds for Jacobi Operators on Star-Like Graphs

Netanel Levi; Tal Malinovitch

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arXiv · 2504.11628

Spectral Multiplicity Bounds for Jacobi Operators on Star-Like Graphs

Netanel Levi·Tal Malinovitch

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Abstract

We study the spectral multiplicity of Jacobi operators on star-like graphs with $m$ branches. Recently, it was established that the multiplicity of the singular continuous spectrum is at most $m$. Building on these developments and using tools from the theory of generalized eigenfunction expansions, we improve this bound by showing that the singular continuous spectrum has multiplicity at most $m-1$. We also show that this bound is sharp, namely, we construct operators with purely singular continuous spectrum of multiplicity $m-1$.

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BibTeX RIS

Netanel Levi, Tal Malinovitch. 2025-04-15. Spectral Multiplicity Bounds for Jacobi Operators on Star-Like Graphs. https://arxiv.org/abs/2504.11628

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