Effective equilibrium states in the colored-noise model for active matter II. A unified framework for phase equilibria, structure and mechanical properties

Wittmann, René; Marini Bettolo Marconi, Umberto; Maggi, C.; Brader, Joseph M.

doi:10.1088/1742-5468/aa8c37

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Journal article

Effective equilibrium states in the colored-noise model for active matter II. A unified framework for phase equilibria, structure and mechanical properties

Wittmann, René Department of Physics, University of Fribourg, Switzerland
Marini Bettolo Marconi, Umberto Scuola di Scienze e Tecnologie, Universit? di Camerino, Via Madonna delle Carceri, Camerino, INFN Perugia, Italy
Maggi, C. NANOTEC-CNR, Institute of Nanotechnology, Soft and Living Matter Laboratory, Roma, Italy
Brader, Joseph M. Department of Physics, University of Fribourg, Switzerland

2017

Published in:

Journal of Statistical Mechanics: Theory and Experiment. - 2017, vol. 2017, no. 11, p. 113208

English Active particles driven by colored noise can be approximately mapped onto a system that obeys detailed balance. The effective interactions which can be derived for such a system allow the description of the structure and phase behavior of the active fluid by means of an effective free energy. In this paper we explain why the related thermodynamic results for pressure and interfacial tension do not represent the results one would measure mechanically. We derive a dynamical density functional theory, which in the steady state simultaneously validates the use of effective interactions and provides access to mechanical quantities. Our calculations suggest that in the colored-noise model the mechanical pressure in the coexisting phases might be unequal and the interfacial tension can become negative.

Faculty

Faculté des sciences et de médecine

Department

Département de Physique

Language