Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Instabilities and diffusion in a hydrodynamic model of a fluid membrane
  coupled to a thin active fluid layer   We construct a coarse-grained effective two-dimensional (2d) hydrodynamic
theory as a theoretical model for a coupled system of a fluid membrane and a
thin layer of a polar active fluid in its ordered state that is anchored to the
membrane. We show that such a system is prone to generic instabilities through
the interplay of nonequilibrium drive, polar order and membrane fluctuation. We
use our model equations to calculate diffusion coefficients of an inclusion in
the membrane and show that their values depend strongly on the system size, in
contrast to their equilibrium values. Our work extends the work of S.
Sankararaman and S. Ramaswamy [Phys. Rev. Lett., 102, 118107 (2009)] to a
coupled system of a fluid membrane and an ordered active fluid layer. Our model
is broadly inspired by and should be useful as a starting point for theoretical
descriptions of the coupled dynamics of a cell membrane and a cortical actin
layer anchored to it.

2
The categories of this paper are: math
13
The categories of this paper are: quant-ph
36
The categories of this paper are: cmp-lg
20
The categories of this paper are: acc-phys
35
The categories of this paper are: mtrl-th
10
The categories of this paper are: q-bio
31
The categories of this paper are: ao-sci
21
The categories of this paper are: adap-org
30
The categories of this paper are: q-alg
25
The categories of this paper are: patt-sol
18
The categories of this paper are: econ
8
The categories of this paper are: hep-ex
5
The categories of this paper are: gr-qc
14
The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga
9
The categories of this paper are: nlin