Mathematics – Functional Analysis
Scientific paper
1999-12-15
Journal of Fourier Analysis and Applications 5 (1999), 289--306
Mathematics
Functional Analysis
AMS-LaTeX; 18 pages, 1 figure comprising 2 EPS diagrams; revision provides the graphics files for these figures (no other chan
Scientific paper
Let $ \Omega \subset R^d $ have finite positive Lebesgue measure, and let $ \mathcal{L}^{2}(\Omega) $ be the corresponding Hilbert space of $ \mathcal{L}^{2} $-functions on $ \Omega $. We shall consider the exponential functions $ e_{\lambda} $ on $ \Omega $ given by $ e_{\lambda}(x)=e^{i2\pi\lambda x} $. If these functions form an orthogonal basis for $ \mathcal{L}^{2}(\Omega) $, when $ \lambda $ ranges over some subset $ \Lambda $ in $ R^d $, then we say that $ (\Omega,\Lambda) $ is a spectral pair, and that $ \Lambda $ is a spectrum. We conjecture that $ (\Omega,\Lambda) $ is a spectral pair if and only if the translates of some set $ \Omega' $ by the vectors of $ \Lambda $ tile $ R^d $. In the special case of $ \Omega=I^d $, the $ d $-dimensional unit cube, we prove this conjecture, with $ \Omega'=I^d $, for $ d \leq 3 $, describing all the tilings by $ I^d $, and for all $ d $ when $ \Lambda $ is a discrete periodic set. In an appendix we generalize the notion of spectral pair to measures on a locally compact abelian group and its dual.
Jorgensen Palle E. T.
Pedersen Steen
No associations
LandOfFree
Spectral pairs in Cartesian coordinates does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Spectral pairs in Cartesian coordinates, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Spectral pairs in Cartesian coordinates will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-580943