Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Geometric characterizations of some classes of operators in C*-algebras
  and von Neumann algebras   We present geometric characterizations of the partial isometries, unitaries,
and invertible operators in C*-algebras and von Neumann algebras.

37
The categories of this paper are: supr-con
7
The categories of this paper are: hep-th
9
The categories of this paper are: nlin
6
The categories of this paper are: astro-ph
31
The categories of this paper are: ao-sci
27
The categories of this paper are: comp-gas
5
The categories of this paper are: gr-qc
13
The categories of this paper are: quant-ph
1
The categories of this paper are: cs
19
The categories of this paper are: eess
0
The categories of this paper are: hep-ph
4
The categories of this paper are: cond-mat
8
The categories of this paper are: hep-ex
32
The categories of this paper are: atom-ph
14
The categories of this paper are: math-ph
25
The categories of this paper are: patt-sol