Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Global Well-Posedness of 2D Second Grade Fluid Equations in Exterior
  Domain   In this article, we consider 2D second grade fluid equations in exterior
domain with Dirichlet boundary conditions. For initial data $\boldsymbol{u}_0
\in \boldsymbol{H}^3(\Omega)$, the system is shown to be global well-posed.
Furthermore, for arbitrary $T > 0$ and $s \geq 3$, we prove that the solution
belongs to $L^\infty([0, T]; \boldsymbol{H}^s(\Omega))$ provided that
$\boldsymbol{u}_0$ is in $\boldsymbol{H}^s(\Omega)$.

27
The categories of this paper are: comp-gas
6
The categories of this paper are: astro-ph
22
The categories of this paper are: chao-dyn
12
The categories of this paper are: nucl-th
25
The categories of this paper are: patt-sol
3
The categories of this paper are: physics
15
The categories of this paper are: nucl-ex
4
The categories of this paper are: cond-mat
36
The categories of this paper are: cmp-lg
11
The categories of this paper are: hep-lat
23
The categories of this paper are: solv-int
16
The categories of this paper are: stat
8
The categories of this paper are: hep-ex
14
The categories of this paper are: math-ph
1
The categories of this paper are: cs
10
The categories of this paper are: q-bio