Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Scaling regimes of active turbulence with external dissipation   Active fluids exhibit complex turbulent-like flows at low Reynolds number.
Recent work predicted that 2d active nematic turbulence follows universal
scaling laws. However, experimentally testing these predictions is conditioned
by the coupling to the 3d environment. Here, we measure the spectrum of the
kinetic energy, $E(q)$, in an active nematic film in contact with a passive oil
layer. At small and intermediate scales, we find the scaling regimes $E(q)\sim
q^{-4}$ and $E(q)\sim q^{-1}$, respectively, in agreement with the theoretical
prediction for 2d active nematics. At large scales, however, we find a new
scaling $E(q)\sim q$, which emerges when the dissipation is dominated by the 3d
oil layer. In addition, we derive an explicit expression for the spectrum that
spans all length scales, thus explaining and connecting the different scaling
regimes. This allows us to fit the data and extract the length scale that
controls the crossover to the new large-scale regime, which we tune by varying
the oil viscosity. Overall, our work experimentally demonstrates the emergence
of universal scaling laws in active turbulence, and it establishes how the
spectrum is affected by external dissipation.

25
The categories of this paper are: patt-sol
7
The categories of this paper are: hep-th
28
The categories of this paper are: alg-geom
17
The categories of this paper are: q-fin
18
The categories of this paper are: econ
27
The categories of this paper are: comp-gas
34
The categories of this paper are: chem-ph
16
The categories of this paper are: stat
6
The categories of this paper are: astro-ph
24
The categories of this paper are: dg-ga
19
The categories of this paper are: eess
10
The categories of this paper are: q-bio
35
The categories of this paper are: mtrl-th
14
The categories of this paper are: math-ph
11
The categories of this paper are: hep-lat
26
The categories of this paper are: bayes-an