Pith. sign in

REVIEW 2 cited by

Critical almost Mathieu operator: hidden singularity, gap continuity, and the Hausdorff dimension of the spectrum

Not yet reviewed by Pith; the record is open.

This paper has not been read by Pith yet. Machine review is queued; the pith claim, tier, and objections will appear here once it completes.

SPECIMEN: schema-true, not a live event

T0 review · schema-true

One-sentence machine reading of the paper's core claim.

pith:XXXXXXXX · record.json · timestamp

arxiv 1909.04429 v1 pith:6N5XFV2K submitted 2019-09-10 math.SP math-phmath.MP

classification math.SPmath-phmath.MP
keywords almostdimensionhausdorffspectrumcontinuitycriticalmathieuproblem
verification ladder T0 review T1 audit T2 compute T3 formal

Signed reviews

No signed human review yet.

0 comments
read the original abstract

We prove almost Lipshitz continuity of spectra of singular quasiperiodic Jacobi matrices and obtain a representation of the critical almost Mathieu family that has a singularity. This allows us to prove that the Hausdorff dimension of its spectrum is not larger than 1/2 for all irrational frequencies, solving a long-standing problem. Other corollaries include two very elementary proofs of zero measure of the spectrum (Problem 5 in [41]) and a similar Hausdorff dimension result for the quantum graph graphene.

Discussion (0). Continue with ORCID to comment.

Forward citations

Cited by 2 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. Full citation record

  1. Log-Hausdorff multifractality of the absolutely continuous spectral measure of the almost Mathieu operator

    math-ph 2025-09 conditional novelty 7.0 of 10

    For subcritical almost Mathieu operators with Diophantine frequency, each exceptional lower-scaling-index level set has Hausdorff dimension 0 but log-Hausdorff dimension 1.

  2. Cantor spectrum for multidimensional quasi-periodic Schr\"odinger operators

    math.SP 2025-06 reject novelty 7.0 of 10

    A dense, positive-Hausdorff-dimension set of frequencies gives the multidimensional almost Mathieu operator a zero-measure Cantor spectrum, and critical almost Mathieu spectra can have arbitrarily small positive box d...

Pith tools