Speaker
Prof.
Bert Schroer
Description
Presently quantum field theory is undergoing significant changes which started with the solution of an old problem: the quantum field theory behind the third positive energy Wigner representation class ("infinite spin")in terms of of string-localized generating fields. This in turn led to foundational changes for the other two classes: the m>0 and the m=0
finite helicity class The stringlocal description of these two classes leads among other things to the extension of renormalizability for any spin and the "adiabatic
equivalence principle" makes sure that the physical content is the same as in the nonrenormalizable pointlike description i.e. stringlocal fields play the role of a different "field coordinatization" of the same QFT. The special case m>0, s=1 amounts to a Hilbert space analog of the BRST operator gauge description in Krein space in which the subalgebra of
pointlike fields coincides with the gauge invariant observables. The stringlike approach leads to new insights into the Higgs mechanism and confinement. Last but not least it reveals that the noncompact localization properties of the third Wigner class matter as those which astrophysicists ascribe to dark matter.
