Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Observational constraints and stability in viscous $f(T,\mathcal{T})$
  gravity   In this paper, we study the $f(T,\mathcal{T})$ gravity model in the presence
of the bulk viscosity by the flat-FRW metric. The field equation is obtained by
teleparallel gravity with tetrad field. The universe components are considered
as matter and dark energy which the dark energy component associates from the
viscous $f(T,\mathcal{T})$ gravity. After calculating the Friedmann equations,
we obtain the energy density, the pressure and the EoS of dark energy in terms
of the redshift parameter. Afterward, we plot the corresponding cosmological
parameters versus the redshift parameter and examine the accelerated expansion
of the universe. In the end, we explore the system stability by a function
called the speed sound parameter.

31
The categories of this paper are: ao-sci
25
The categories of this paper are: patt-sol
24
The categories of this paper are: dg-ga
17
The categories of this paper are: q-fin
1
The categories of this paper are: cs
28
The categories of this paper are: alg-geom
21
The categories of this paper are: adap-org
22
The categories of this paper are: chao-dyn
33
The categories of this paper are: plasm-ph
34
The categories of this paper are: chem-ph
35
The categories of this paper are: mtrl-th
11
The categories of this paper are: hep-lat
12
The categories of this paper are: nucl-th
14
The categories of this paper are: math-ph
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ