Dom<p><a href="https://qoto.org/tags/SoftMatter" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>SoftMatter</span></a> have just published the <a href="https://doi.org/10.1039/D2SM01188C" rel="nofollow noopener" target="_blank">results</a> of a project that Renato Assante, Davide Marenduzzo, Alexander Morozov, and I recently worked on together! What did we do and what’s new? Briefly…</p><p><a href="https://qoto.org/tags/Microswimmer" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>Microswimmer</span></a> suspensions behave in a similar way to fluids containing kinesin and microtubules. Both systems can be described by the same system of three coupled nonlinear <a href="https://qoto.org/tags/PDEs" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>PDEs</span></a>.</p><p>A <a href="https://qoto.org/tags/LinearStabilityAnalysis" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>LinearStabilityAnalysis</span></a> of these equations suggests that variations in concentration across the system don’t significantly affect emergent <a href="https://qoto.org/tags/phaseBehaviour" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>phaseBehaviour</span></a>. How then can we explain <a href="https://qoto.org/tags/experiments" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>experiments</span></a> that show visible inhomogeneities in <a href="https://qoto.org/tags/microtubule" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>microtubule</span></a>–<a href="https://qoto.org/tags/kinesin" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>kinesin</span></a> mixtures, for instance?</p><p>With increasing activity, we move away from the quiescent regime, past the onset of <a href="https://qoto.org/tags/SpontaneousFlow" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>SpontaneousFlow</span></a>, and deeper into the active phase, where <a href="https://qoto.org/tags/nonlinearities" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>nonlinearities</span></a> become more important. What role do concentration inhomogeneities play here?</p><p>We investigated these questions, taking advantage of the <a href="https://qoto.org/tags/openSource" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>openSource</span></a> <a href="https://qoto.org/tags/Dedalus" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>Dedalus</span></a> <a href="https://qoto.org/tags/spectral" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>spectral</span></a> framework to simulate the full nonlinear time evolution. This led us to <strong>predict a <a href="https://qoto.org/tags/novel" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>novel</span></a> regime of <a href="https://qoto.org/tags/spontaneous" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>spontaneous</span></a> <a href="https://qoto.org/tags/microphaseSeparation" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>microphaseSeparation</span></a> into active (nematically ordered) and passive domains</strong>.</p><p>Active flow arrests macrophase separation in this regime, counteracting domain coarsening due to thermodynamic coupling between active matter concentration and <a href="https://qoto.org/tags/nematic" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>nematic</span></a> order. As a result, domains reach a characteristic size that decreases with increasing activity.</p><p>This regime is one part of the <a href="https://qoto.org/tags/PhaseDiagram" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>PhaseDiagram</span></a> we mapped out. Along with our other findings, you can read all about it <a href="https://doi.org/10.1039/D2SM01188C" rel="nofollow noopener" target="_blank">here</a>!</p><p>low <a href="https://qoto.org/tags/ReynoldsNumber" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>ReynoldsNumber</span></a> <a href="https://qoto.org/tags/turbulence" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>turbulence</span></a> <a href="https://qoto.org/tags/ActiveTurbulence" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>ActiveTurbulence</span></a> <a href="https://qoto.org/tags/CahnHilliard" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>CahnHilliard</span></a> <a href="https://qoto.org/tags/ActiveMatter" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>ActiveMatter</span></a> <a href="https://qoto.org/tags/NavierStokes" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>NavierStokes</span></a> <a href="https://qoto.org/tags/BerisEdwards" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>BerisEdwards</span></a> <a href="https://qoto.org/tags/CondensedMatter" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>CondensedMatter</span></a> <a href="https://qoto.org/tags/PhaseTransitions" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>PhaseTransitions</span></a> <a href="https://qoto.org/tags/TheoreticalPhysics" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>TheoreticalPhysics</span></a> <a href="https://qoto.org/tags/BioPhysics" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>BioPhysics</span></a> <a href="https://qoto.org/tags/StatisticalPhysics" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>StatisticalPhysics</span></a> <a href="https://qoto.org/tags/FluidDynamics" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>FluidDynamics</span></a> <a href="https://qoto.org/tags/ComputationalPhysics" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>ComputationalPhysics</span></a> <a href="https://qoto.org/tags/Simulation" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>Simulation</span></a> <a href="https://qoto.org/tags/FieldTheory" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>FieldTheory</span></a> <a href="https://qoto.org/tags/paperthread" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>paperthread</span></a> <a href="https://qoto.org/tags/NewPaper" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>NewPaper</span></a> <a href="https://qoto.org/tags/science" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>science</span></a> <a href="https://qoto.org/tags/research" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>research</span></a> <a href="https://qoto.org/tags/ActiveGel" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>ActiveGel</span></a> <a href="https://qoto.org/tags/activeNematic" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>activeNematic</span></a> <a href="https://qoto.org/tags/analytic" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>analytic</span></a> <a href="https://qoto.org/tags/cytoskeleton" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>cytoskeleton</span></a> <a href="https://qoto.org/tags/hydrodynamics" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>hydrodynamics</span></a> <a href="https://qoto.org/tags/MPI" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>MPI</span></a> <a href="https://qoto.org/tags/theory" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>theory</span></a></p>