TITLE:
A Note on the Structure of Affine Subspaces of L2(Rd)
AUTHORS:
Fengying Zhou, Xiaoyong Xu
KEYWORDS:
Affine Subspace, Reducing Subspace, Shift Invariant Subspace, Orthogonal Sum
JOURNAL NAME:
Advances in Pure Mathematics,
Vol.5 No.2,
January
28,
2015
ABSTRACT: This paper investigates the structure of general affine subspaces of L2(Rd) . For a d × d expansive matrix A, it shows that
every affine subspace can be decomposed as an orthogonal sum of spaces each of
which is generated by dilating some shift invariant space in this affine
subspace, and every non-zero and non-reducing affine subspace is the orthogonal
direct sum of a reducing subspace and a purely non-reducing subspace, and every
affine subspace is the orthogonal direct sum of at most three purely
non-reducing subspaces when |detA| =
2.