Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Physics of collisionless shocks - theory and simulation   Collisionless shocks occur in various fields of physics. In the context of
space and astrophysics they have been investigated for many decades. However, a
thorough understanding of shock formation and particle acceleration is still
missing. Collisionless shocks can be distinguished into electromagnetic and
electrostatic shocks. Electromagnetic shocks are of importance mainly in
astrophysical environments and they are mediated by the Weibel or filamentation
instability. In such shocks, charged particles gain energy by diffusive shock
acceleration. Electrostatic shocks are characterized by a strong electrostatic
field, which leads to electron trapping. Ions are accelerated by reflection
from the electrostatic potential. Shock formation and particle acceleration
will be discussed in theory and simulations.

17
The categories of this paper are: q-fin
10
The categories of this paper are: q-bio
12
The categories of this paper are: nucl-th
26
The categories of this paper are: bayes-an
33
The categories of this paper are: plasm-ph
24
The categories of this paper are: dg-ga
35
The categories of this paper are: mtrl-th
20
The categories of this paper are: acc-phys
15
The categories of this paper are: nucl-ex
11
The categories of this paper are: hep-lat
7
The categories of this paper are: hep-th
31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg
37
The categories of this paper are: supr-con
8
The categories of this paper are: hep-ex
1
The categories of this paper are: cs