Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Singular spaces, groupoids and metrics of positive scalar curvature   We define and study, under suitable assumptions, the fundamental class, the
index class and the rho class of a spin Dirac operator on the regular part of a
spin stratified pseudomanifold. More singular structures, such as singular
foliations, are also treated. We employ groupoid techniques in a crucial way;
however, an effort has been made in order to make this article accessible to
readers with only a minimal knowledge of groupoids. Finally, whenever
appropriate, a comparison between classical microlocal methods and groupoids
methods has been provided.

27
The categories of this paper are: comp-gas
12
The categories of this paper are: nucl-th
23
The categories of this paper are: solv-int
31
The categories of this paper are: ao-sci
4
The categories of this paper are: cond-mat
37
The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
0
The categories of this paper are: hep-ph
8
The categories of this paper are: hep-ex
6
The categories of this paper are: astro-ph
22
The categories of this paper are: chao-dyn
11
The categories of this paper are: hep-lat
32
The categories of this paper are: atom-ph
16
The categories of this paper are: stat
14
The categories of this paper are: math-ph
20
The categories of this paper are: acc-phys