Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Lagrangian coordinates for the sticky particle system   The sticky particle system is a system of partial differential equations
which assert the conservation of mass and momentum of a collection of particles
that interact only via inelastic collisions. These equations arise in
Zel'dovich's theory for the formation of large scale structures in the
universe. We will show that this system of equations has a solution in one
spatial dimension for given initial conditions by generating a trajectory
mapping in Lagrangian coordinates.

8
The categories of this paper are: hep-ex
10
The categories of this paper are: q-bio
31
The categories of this paper are: ao-sci
7
The categories of this paper are: hep-th
3
The categories of this paper are: physics
24
The categories of this paper are: dg-ga
32
The categories of this paper are: atom-ph
21
The categories of this paper are: adap-org
0
The categories of this paper are: hep-ph
20
The categories of this paper are: acc-phys
26
The categories of this paper are: bayes-an
29
The categories of this paper are: funct-an
1
The categories of this paper are: cs
28
The categories of this paper are: alg-geom
19
The categories of this paper are: eess
23
The categories of this paper are: solv-int