<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div style="font-family: HelveticaNeue;"><font face="HelveticaNeue">Dear Soft Matter & Complex Systems Colleagues and Friends,</font></div><div><div style="font-family: HelveticaNeue;"><font face="HelveticaNeue"><br></font></div><div style="font-family: HelveticaNeue;"><font face="HelveticaNeue">On Friday 5 December 2025 at 9:30 AM at the UW Faculty of Physics (Pasteura 5, Warsaw; room 1.40) we are hosting a seminar, during which </font></div><div style="font-family: HelveticaNeue;"><font face="HelveticaNeue"><br></font></div><div style="margin: 0px; font-width: normal; line-height: normal; min-height: 14px;"><font face="HelveticaNeue" style="font-family: HelveticaNeue;"><b>Antoine Sellier</b></font><font face="HelveticaNeue" style="font-family: HelveticaNeue;"><b> </b>(</font><font face="HelveticaNeue">LadHyX, Ecole Polytechnique, Palaiseau, France))</font></div><div style="font-family: HelveticaNeue; margin: 0px; font-width: normal; line-height: normal; min-height: 14px;"><font face="HelveticaNeue"><br></font></div><div style="font-family: HelveticaNeue; margin: 0px; font-width: normal; line-height: normal;"><font face="HelveticaNeue">will give a talk</font></div><div style="margin: 0px; font-width: normal; line-height: normal; min-height: 14px;"><div><h2 style="margin: 6px 0px 12px; padding: 0px;"><font face="HelveticaNeue"><span style="font-size: 12px;">Stokes flow about a collection of slip solid bodies</span></font></h2><h2 style="font-family: HelveticaNeue; margin: 6px 0px 12px; padding: 0px;"><b style="caret-color: rgb(68, 68, 68);"><font face="HelveticaNeue" style="font-size: 12px;">Abstract</font></b></h2></div><div><div><font face="HelveticaNeue">A boundary efficient and accurate method is proposed and numerically worked out to calculate, in the creeping flow regime, the resistance matrix of a cluster made of N arbitrarily-shaped slip solid bodies. The slip on each body curved surface is modeled using the widely-employed Navier slip condition and there is no restriction on the number N of bodies. Moreover, the task reduces to the treatment of 6N boundary-integral equations on the cluster surface and it is no use calculating the Stokes flow about the moving particles. Comparisons with the literature for one sphere (singularity method) and for two-interacting spheres (multipole method) will be presented. Finally, some numerical results for slip ellipsoids and the gravity-driven motion of two slip interacting spheres will be given and discussed.</font></div></div><div style="font-family: HelveticaNeue;"><br></div></div><div style="font-family: HelveticaNeue; margin: 0px; font-width: normal; line-height: normal;"><font face="HelveticaNeue">We warmly welcome everyone to attend the talk and the Soft Matter Coffee Break after the seminar, held in room 2.63 (2nd floor).</font></div></div><div style="font-family: HelveticaNeue;"><font face="HelveticaNeue"><br></font></div><div style="font-family: HelveticaNeue;"><div dir="auto" style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div style="margin: 0px; font-width: normal; line-height: normal;"><font face="HelveticaNeue">Maria Ekiel-Jeżewska</font></div><div style="margin: 0px; font-width: normal; line-height: normal;"><font face="HelveticaNeue">Maciej Lisicki</font></div><div style="margin: 0px; font-width: normal; line-height: normal;"><font face="HelveticaNeue">Piotr Szymczak</font></div><div style="margin: 0px; font-width: normal; line-height: normal;"><font face="HelveticaNeue">Panagiotis Theodorakis</font></div></div></div></body></html>