BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Liquid crystals\, topological defects\, and morphogenesis - Farzan
  Vafa (Harvard University)
DTSTART:20230831T140000Z
DTEND:20230831T150000Z
UID:TALK204568@talks.cam.ac.uk
DESCRIPTION:We begin by investigating the ground-state configurations of t
 wo-dimensional liquid crystals with p-fold rotational symmetry (p-atics) o
 n cones. We show that the cone apex develops an effective topological char
 ge\, which in analogy to electrostatics\, leads to defect absorption and e
 mission at the cone apex as the deficit angle of the cone is varied. We th
 en apply this formalism to develop a minimal model of morphogenesis of a s
 urface where the dynamics of the intrinsic geometry is diffusive growth so
 urced by topological defects. We show that a positive (negative) defect ca
 n dynamically generate a cone (hyperbolic cone). We analytically explain f
 eatures of the growth profile as a function of position and time\, and pre
 dict that in the presence of a positive defect\, a bump forms with height 
 profile h(t) ~ t^(1/2) for early times t. To incorporate the effect of the
  mean curvature\, we exploit the fact that for axisymmetric surfaces\, the
  extrinsic geometry can be deduced entirely by the intrinsic geometry. We 
 find that the resulting stationary geometry\, for polar order and small be
 nding modulus\, is a deformed football. We apply our framework to the simp
 le animal Hydra.&nbsp\;
LOCATION:Discussion Room\, Newton Institute
END:VEVENT
END:VCALENDAR