Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Topological waves in fluids with odd viscosity   Fluids in which both time-reversal and parity are broken can display a
dissipationless viscosity that is odd under each of these symmetries. Here, we
show how this odd viscosity has a dramatic effect on topological sound waves in
fluids, including the number and spatial profile of topological edge modes. Odd
viscosity provides a short-distance cutoff that allows us to define a bulk
topological invariant on a compact momentum space. As the sign of odd viscosity
changes, a topological phase transition occurs without closing the bulk gap.
Instead, at the transition point, the topological invariant becomes ill-defined
because momentum space cannot be compactified. This mechanism is unique to
continuum models and can describe fluids ranging from electronic to chiral
active systems.

9
The categories of this paper are: nlin
15
The categories of this paper are: nucl-ex
35
The categories of this paper are: mtrl-th
37
The categories of this paper are: supr-con
24
The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
10
The categories of this paper are: q-bio
26
The categories of this paper are: bayes-an
23
The categories of this paper are: solv-int
16
The categories of this paper are: stat
36
The categories of this paper are: cmp-lg
3
The categories of this paper are: physics
19
The categories of this paper are: eess
33
The categories of this paper are: plasm-ph
31
The categories of this paper are: ao-sci
6
The categories of this paper are: astro-ph