Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On R-duals of type III in Hilbert spaces   Following work by Casazza, Kutyniok and Lammers, and extensions by Stoeva and
Christensen, we provide some novel characterizations of R-dual sequences of
type III in Hilbert spaces. We systematically extend the construction procedure
by basing it on a choice of an antiunitary involution. For certain classes of
R-duals of type III, we derive a representation of the associated frame
operator in terms of spectral measures.

4
The categories of this paper are: cond-mat
35
The categories of this paper are: mtrl-th
15
The categories of this paper are: nucl-ex
36
The categories of this paper are: cmp-lg
33
The categories of this paper are: plasm-ph
9
The categories of this paper are: nlin
25
The categories of this paper are: patt-sol
19
The categories of this paper are: eess
0
The categories of this paper are: hep-ph
12
The categories of this paper are: nucl-th
6
The categories of this paper are: astro-ph
34
The categories of this paper are: chem-ph
18
The categories of this paper are: econ
3
The categories of this paper are: physics
16
The categories of this paper are: stat
17
The categories of this paper are: q-fin