Cantor measures with odd base do not admit Fourier frames
It is unknown whether certain Cantor measures, such as the middle-third Cantor measure, admit a Fourier frame, a question of Strichartz. Frame-spectrality generalizes the existence of an orthonormal Fourier basis.
The authors prove that the Cantor measure with base b does not admit a Fourier frame for any odd integer b>1. The argument uses Haar functions on Cantor sets, self-similarity of the measure, and a contradiction argument based on estimates of the Fourier transform modulus. The main result is additionally formalized in Lean 4, relying on Mathlib's measure-theoretic definitions, with the theorem statement curated by the authors and proof files partly generated by large language models.
The Cantor measure with odd base b admits no Fourier frame, answering Strichartz's question for the middle-third Cantor measure. The main theorem was Lean-verified via the statement NoFourierFrameExists.
