121 research outputs found
Measure Functions for Frames
This paper addresses the natural question: ``How should frames be compared?''
We answer this question by quantifying the overcompleteness of all frames with
the same index set. We introduce the concept of a frame measure function: a
function which maps each frame to a continuous function. The comparison of
these functions induces an equivalence and partial order that allows for a
meaningful comparison of frames indexed by the same set. We define the
ultrafilter measure function, an explicit frame measure function that we show
is contained both algebraically and topologically inside all frame measure
functions. We explore additional properties of frame measure functions, showing
that they are additive on a large class of supersets-- those that come from so
called non-expansive frames. We apply our results to the Gabor setting,
computing the frame measure function of Gabor frames and establishing a new
result about supersets of Gabor frames.Comment: 54 pages, 1 figure; fixed typos, reformatted reference
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