Work

Polynomial Spectral Gap Estimates for Finitely Differentiable Quasi-Periodic Schrödinger Operators

Year: 2026
Type: preprint
Abstract: We prove polynomial upper bounds on spectral gaps of quasi-periodic Schrödinger operators with small $C^{k}$ potentials and Diophantine frequencies. For sufficiently large $k$, the decay exponent is $k-34τ$, where $τ$ is the Diophantine exponent. We construct examples with lower bounds along infinitely many gap labels, showing that the leading coefficient $1$ of $k$ is asymptotically optimal. The proof uses quantitative reducibility and the Moser-Pöschel argument.
Language: English
Open Access status: green
OpenAlex ID: W7223150475
Cites: 6
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Related to: 10