Data:	Venerdì 14 Ottobre 2011, h. 14:00
Luogo:	Dip. Matematica, Univ. Roma "La Sapienza"
Speaker:	Detlev Buchholz, Univ. of Göttingen
Titolo:	Infrared Problems and Sector Analysis. Old Wisdom and Recent Progress
Abstract:	The determination and analysis of the superselection structure in quantum field theories with long range forces is hampered by the appearance of an abundance of sectors which vary in marginal infrared properties. Because of this difficulty a meaningful definition and classification of sector statistics and of global gauge symmetries has been missing to date. In this talk some progress on this longstanding problem will be discussed; it is based upon a strikingly simple geometric resolution of the infrared difficulties.