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VERSION:2.0
CALSCALE:GREGORIAN
PRODID:UW-Physics-TWaP
BEGIN:VEVENT
SEQUENCE:1
UID:UW-Physics-Event-4571
DTSTART:20170824T160000Z
DURATION:PT1H0M0S
DTSTAMP:20201025T225234Z
LAST-MODIFIED:20171120T163636Z
LOCATION:5280 Chamberlin Hall
SUMMARY:O(N) invariance of the multi-field bounce\, Theory Seminar (Hi
gh Energy/Cosmology)\, Kfir Blum\, Weizmann Institute of Science
DESCRIPTION:In his 1977 paper on vacuum decay in field theory: The Fat
e of the False Vacuum\, Coleman considered the problem of a single sca
lar field and assumed that the minimum action tunnelling field configu
ration\, the bounce\, is invariant under O(4) rotations in Euclidean s
pace. A proof of the O(4) invariance of the bounce was provided later
by Coleman\, Glaser\, and Martin (CGM)\, who extended the proof to N>2
Euclidean dimensions but\, again\, restricted non-trivially to a sing
le scalar field. As far as we know a proof of O(N) invariance of the b
ounce with more than one scalar fields has not been reported in the QF
T literature\, even though it was assumed in many works since. We make
progress towards closing this gap. Following CGM we define the reduce
d problem of finding a field configuration minimizing the kinetic ener
gy at fixed potential energy. Given a solution of the reduced problem\
, the minimum action bounce can always be obtained from it by means of
a scale transformation. We show that if a solution of the reduced pro
blem exists\, then it and the minimum action bounce derived from it ar
e indeed O(N) symmetric. We review complementary results in the mathem
atical literature that established the existence of a minimizer under
specified criteria.
URL:https://www.physics.wisc.edu/twap/?id=4571
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