Abstract
A set Ω ⊂ ℝ2 is said to be spectral if the space L2(Ω) has an orthogonal basis of exponential functions. It is well-known that in many respects, spectral sets “behave like” sets which can tile the space by translations. This suggests a conjecture that a product set Ω = A × B is spectral if and only if the factors A and B are both spectral sets. We recently proved this in the case when A is an interval in dimension one. The main result of the present paper is that the conjecture is true also when A is a convex polygon in two dimensions. We discuss this result in connection with the conjecture that a convex polytope Ω is spectral if and only if it can tile by translations.
Original language | English (US) |
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Pages (from-to) | 409-441 |
Number of pages | 33 |
Journal | Journal d'Analyse Mathematique |
Volume | 140 |
Issue number | 2 |
DOIs | |
State | Published - Mar 1 2020 |
Funding
Research supported by ISF grant No. 227/17 and ERC Starting Grant No. 713927.
ASJC Scopus subject areas
- Analysis
- General Mathematics