Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the Reidemeister spectrum and the $R_{\infty}$ property for some free
  nilpotent groups   We describe the Reidemeister spectrum $Spec_RG$ for $G = N_{rc},$ the free
nilpotent group of rank $r$ and class $c,$ in the cases: $r \in {\mathbb N}$
and $c = 1;$ $r = 2, 3$ and $c = 2;$ $ r = 2$ and $c = 3,$ and prove that any
group $N_{2c}$ for $c \geq 4$ satisfies to the $R_{\infty}$ property. As a
consequence we obtain that every free solvable group $S_{2t}$ of rank 2 and
class $t \geq 2$ (in particular the free metabelian group $M_2 = S_{22}$ of
rank 2) satisfies to the $R_{\infty}$ property. Moreover, we prove that any
free solvable group $S_{rt}$ of rank $r \geq 2$ and class $t$ big enough also
satisfies to the $R_{\infty}$ property.

18
The categories of this paper are: econ
12
The categories of this paper are: nucl-th
23
The categories of this paper are: solv-int
9
The categories of this paper are: nlin
14
The categories of this paper are: math-ph
16
The categories of this paper are: stat
36
The categories of this paper are: cmp-lg
21
The categories of this paper are: adap-org
26
The categories of this paper are: bayes-an
29
The categories of this paper are: funct-an
13
The categories of this paper are: quant-ph
34
The categories of this paper are: chem-ph
37
The categories of this paper are: supr-con
6
The categories of this paper are: astro-ph
1
The categories of this paper are: cs
28
The categories of this paper are: alg-geom