Inclusions and Disorder
Flexible passive inclusions can spontaneously curve and move due to unbalanced pressures:
An asymmetric inclusion will experience a force, balanced by counter-flow current flow of active particles:
Asymmetric inclusion acts as pump; conservation of current leads to long-range modulations of active particle density
Long-range density/current disturbances lead to long-range interactions between inclusions, and with containing boundaries
Y. Ben Dor, Y. Kafri, M. Kardar, J. Tailleur, Phys. Rev. E 106, 044604 (2022)
Active particles moving on a disordered landscape:
On coarse scales, the random landscape can be regarded as a collection of randomly placed pumps (fixed inclusions)
Density response of non-interacting active particles on such landscape can be obtained by superposition:
Sunghan Ro, Y. Kafri, M. Kardar, J. Tailleur, Phys. Rev. Lett. 126, 048003 (2021)