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VERSION:2.0
CALSCALE:GREGORIAN
PRODID:UW-Madison-Physics-Events
BEGIN:VEVENT
SEQUENCE:1
UID:UW-Physics-Event-9520
DTSTART:20260312T150000Z
DTEND:20260312T160000Z
DTSTAMP:20260413T084032Z
LAST-MODIFIED:20260213T205749Z
LOCATION:5310 Chamberlin Hall
SUMMARY:Only the ambidextrous can flock: chirality destroys order in p
 olar active matter\, R. G. Herb Condensed Matter Seminar\, John Toner\
 , University of Oregon
DESCRIPTION:I'll show that  flocks of chiral living creatures (i.e.\, 
 organisms that are right or left handed) moving on a surface\,  compos
 ed of critters can not form a long range ordered flocking state (i.e.\
 , a state in which the spatially averaged velocity vector <vec{v}> is 
 non-zero\,)  even though it is well-known that they can order in this 
 way if they are achiral. "Immortal" flocks (flocks in which the creatu
 res are not being born and dying on the time scales iof interest) prov
 e to be much more nearly ordered than "Malthusian" flocks in which bir
 th and death do occur. Immortal flocks have a phase which\, although n
 ot truly long-range ordered\,  better ordered than the "Kosterlitz-Tho
 uless quasi-long-range ordered phase"  (KT phase) of the equilibrium 2
 d XY model. This phase exhibits non-unversal exponents of a type very 
 different from the familiar non-universal exponents of the KT phase.
URL:https://www.physics.wisc.edu/events/?id=9520
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