Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Differential-activity driven instabilities in biphasic active matter   Active stresses can cause instabilities in contractile gels and living
tissues. Here we describe a generic hydrodynamic theory that treats these
systems as a mixture of two phases of varying activity and different mechanical
properties. We find that differential activity between the phases provides a
mechanism causing a demixing instability. We follow the nonlinear evolution of
the instability and characterize a phase diagram of the resulting patterns. Our
study complements other instability mechanisms in mixtures such as differential
growth, shape, motion or adhesion.

37
The categories of this paper are: supr-con
2
The categories of this paper are: math
17
The categories of this paper are: q-fin
12
The categories of this paper are: nucl-th
14
The categories of this paper are: math-ph
26
The categories of this paper are: bayes-an
35
The categories of this paper are: mtrl-th
9
The categories of this paper are: nlin
24
The categories of this paper are: dg-ga
31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg
5
The categories of this paper are: gr-qc
27
The categories of this paper are: comp-gas
7
The categories of this paper are: hep-th
16
The categories of this paper are: stat
29
The categories of this paper are: funct-an