Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On group actions with simple Lebesgue spectrum   In this paper we propose a construction of measure preserving actions of the
group $R^d$ with Lebesgue spectrum of multiplicity one.

6
The categories of this paper are: astro-ph
28
The categories of this paper are: alg-geom
25
The categories of this paper are: patt-sol
18
The categories of this paper are: econ
37
The categories of this paper are: supr-con
21
The categories of this paper are: adap-org
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
14
The categories of this paper are: math-ph
17
The categories of this paper are: q-fin
31
The categories of this paper are: ao-sci
11
The categories of this paper are: hep-lat
20
The categories of this paper are: acc-phys
33
The categories of this paper are: plasm-ph
9
The categories of this paper are: nlin
4
The categories of this paper are: cond-mat