title: Correlation lengths in hydrodynamic models of active nematics.
abstract: We examine the scaling with activity of the emergent length scales that control the nonequilibrium dynamics of an active nematic liquid crystal, using two popular hydrodynamic models that have been employed in previous studies. In both models we find that the chaotic spatio-temporal dynamics in the regime of fully developed active turbulence is controlled by a single active scale determined by the balance of active and elastic stresses, regardless of whether the active stress is extensile or contractile in nature. The observed scaling of the kinetic energy and enstrophy with activity is consistent with our single-length scale argument and simple dimensional analysis. Our results provide a unified understanding of apparent discrepancies in the previous literature and demonstrate that the essential physics is robust to the choice of model.
authors.affiliation: Department of Physics, Durham University, Science Laboratories, South Road, Durham, DH1 3LE, UK. e.j.hemingway@durham.ac.uk.
authors.forename: Ewan J
authors.identifier: http://orcid.org/0000-0001-6152-3858
authors.initials: EJ
authors.lastname: Hemingway
authors.affiliation: Physics Department and Syracuse Soft Matter Program, Syracuse University, Syracuse, NY 13244, USA.
authors.forename: Prashant
authors.initials: P
authors.lastname: Mishra
authors.affiliation: Physics Department and Syracuse Soft Matter Program, Syracuse University, Syracuse, NY 13244, USA and Syracuse Biomaterials Institute, Syracuse University, Syracuse, NY, USA.
authors.forename: M Cristina
authors.initials: MC
authors.lastname: Marchetti
authors.affiliation: Department of Physics, Durham University, Science Laboratories, South Road, Durham, DH1 3LE, UK. e.j.hemingway@durham.ac.uk.
authors.forename: Suzanne M
authors.initials: SM
authors.lastname: Fielding