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SUMMARY:Invariance under reflecting temperature to negative values - David
  McGady -- Copenhagen
DTSTART:20160310T130000Z
DTEND:20160310T140000Z
UID:TALK62743@talks.cam.ac.uk
CONTACT:Dr. Piotr Tourkine
DESCRIPTION:Partition functions' convergence e.g. in statistical mechanics
  seem\ndeeply tied to temperature's positivity. Surprisingly\, one can\nex
 plicitly check that model partition functions -- e.g. the simple\nharmonic
  oscillator\, all Virasoro minimal model characters -- are\ninvariant unde
 r reflecting temperatures to negative values\n(T-reflection)\, up to an ov
 erall phase. Demanding this invariance\,\nmodulo this phase\, selects a un
 ique vacuum energy for a system. Finite\ntemperatures in relativistic quan
 tum field theory (QFT) are introduced\nthrough putting the theory on a cir
 cle of radius 1/T. T-reflection is\nrelated to a generic redundancy associ
 ated with the geometry of the\nthermal circle\, and to global gravitationa
 l anomalies. Further\, it had\nled to 2d/4d correspondences in QFT\, and n
 ew conjectures in number\ntheory.
LOCATION:Potter Room (first floor\, Pav. B)
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