%0 Book Section %1 statphys23_1050 %A Mishra, S. %A Ginelli, F. %A Chate, H. %A Puri, S. %A Ramaswamy, S. %B Abstract Book of the XXIII IUPAP International Conference on Statistical Physics %C Genova, Italy %D 2007 %E Pietronero, Luciano %E Loreto, Vittorio %E Zapperi, Stefano %K aggregation granular nonequilibrium statphys23 systems topic-3 %T Coarsening, clumping and cuspy correlations in active nematics: microscopic and coarse-grained approaches %U http://st23.statphys23.org/webservices/abstract/preview_pop.php?ID_PAPER=1050 %X The statistical mechanics of the ordering of self-driven apolar particles has been shown EPL 62 (2003) 196; PRL 96 (2006) 180602; PRL 97 (2006) 090602 to display striking nonequilibrium features, as a result of the interplay of orientation and particle density . We study these nonequilibrium phenomena in detail through particle-based models and stochastic partial differential equations (PDEs). We derive the PDEs by coarse-graining and show that the crucial particle-currents induced by director curvature in the PDEs are an inevitable consequence of the elementary nonequilibrium moves in the particle model. As a result of these currents, the growth of nematic order from an initially isotropic, homogeneous state is shown to be accompanied by a remarkable clumping of the number density around topological defects. The consequent coarsening of both density and nematic order are characterised by cusps in the short-distance behaviour of the correlation functions, a breakdown of Porod's Law. We identify the origins of this breakdown; in particular, the nature of the noise terms in the equations of motion is shown to play a key role.

@incollection{statphys23_1050, abstract = {The statistical mechanics of the ordering of self-driven apolar particles has been shown [EPL 62 (2003) 196; PRL 96 (2006) 180602; PRL 97 (2006) 090602] to display striking nonequilibrium features, as a result of the interplay of orientation and particle density . We study these nonequilibrium phenomena in detail through particle-based models and stochastic partial differential equations (PDEs). We derive the PDEs by coarse-graining and show that the crucial particle-currents induced by director curvature in the PDEs are an inevitable consequence of the elementary nonequilibrium moves in the particle model. As a result of these currents, the growth of nematic order from an initially isotropic, homogeneous state is shown to be accompanied by a remarkable clumping of the number density around topological defects. The consequent coarsening of both density and nematic order are characterised by cusps in the short-distance behaviour of the correlation functions, a breakdown of Porod's Law. We identify the origins of this breakdown; in particular, the nature of the noise terms in the equations of motion is shown to play a key role.}, added-at = {2007-06-20T10:16:09.000+0200}, address = {Genova, Italy}, author = {Mishra, S. and Ginelli, F. and Chate, H. and Puri, S. and Ramaswamy, S.}, biburl = {https://www.bibsonomy.org/bibtex/2508715ea44eb454790869fa05ccb43b1/statphys23}, booktitle = {Abstract Book of the XXIII IUPAP International Conference on Statistical Physics}, editor = {Pietronero, Luciano and Loreto, Vittorio and Zapperi, Stefano}, interhash = {31e142fff8b6c36233eb976c00b3c90e}, intrahash = {508715ea44eb454790869fa05ccb43b1}, keywords = {aggregation granular nonequilibrium statphys23 systems topic-3}, month = {9-13 July}, timestamp = {2007-06-20T10:16:37.000+0200}, title = {Coarsening, clumping and cuspy correlations in active nematics: microscopic and coarse-grained approaches}, url = {http://st23.statphys23.org/webservices/abstract/preview_pop.php?ID_PAPER=1050}, year = 2007 }