Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum Shock Waves and Domain Walls in the Real-Time Dynamics of a
  Superfluid Unitary Fermi Gas   We show that in the collision of two superfluid fermionic atomic clouds one
observes the formation of quantum shock waves as discontinuities in the number
density and collective flow velocity. Domain walls, which are topological
excitations of the superfluid order parameter, are also generated and exhibit
abrupt phase changes by $\pi$ and slower motion than the shock waves. The
domain walls are distinct from the gray soliton train or number density ripples
formed in the wake of the shock waves and observed in the collisions of
superfluid bosonic atomic clouds. Domain walls with opposite phase jumps appear
to collide elastically.

30
The categories of this paper are: q-alg
10
The categories of this paper are: q-bio
22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom
20
The categories of this paper are: acc-phys
36
The categories of this paper are: cmp-lg
16
The categories of this paper are: stat
37
The categories of this paper are: supr-con
31
The categories of this paper are: ao-sci
15
The categories of this paper are: nucl-ex
0
The categories of this paper are: hep-ph
27
The categories of this paper are: comp-gas
29
The categories of this paper are: funct-an
19
The categories of this paper are: eess
1
The categories of this paper are: cs
8
The categories of this paper are: hep-ex