Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quasi-Einstein structures and almost cosymplectic manifolds   In this article, we study almost cosymplectic manifolds admitting
quasi-Einstein structures $(g, V, m, \lambda)$. First we prove that an almost
cosymplectic $(\kappa,\mu)$-manifold is locally isomorphic to a Lie group if
$(g, V, m, \lambda)$ is closed and on a compact almost
$(\kappa,\mu)$-cosymplectic manifold there do not exist quasi-Einstein
structures $(g, V, m, \lambda)$, in which the potential vector field $V$ is
collinear with the Reeb vector filed $\xi$. Next we consider an almost
$\alpha$-cosymplectic manifold admitting a quasi-Einstein structure and obtain
some results. Finally, for a $K$-cosymplectic manifold with a closed,
non-steady quasi-Einstein structure, we prove that it is $\eta$-Einstein. If
$(g, V, m, \lambda)$ is non-steady and $V$ is a conformal vector field, we
obtain the same conclusion.

16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
13
The categories of this paper are: quant-ph
25
The categories of this paper are: patt-sol
20
The categories of this paper are: acc-phys
0
The categories of this paper are: hep-ph
6
The categories of this paper are: astro-ph
4
The categories of this paper are: cond-mat
19
The categories of this paper are: eess
1
The categories of this paper are: cs
12
The categories of this paper are: nucl-th
8
The categories of this paper are: hep-ex
17
The categories of this paper are: q-fin
15
The categories of this paper are: nucl-ex