Renormalization of Lorentz violating theories by weighted power counting

by Prof. D. Anselmi (Università di Pisa)

Thursday 31 Jan 2008, 16:00 → 18:00 Europe/Rome

aula Conversi - Edificio G. Marconi (Dip. di Fisica - Edificio G. Marconi)

I study local, unitary, renormalizable Lorentz violating quantum field theories. Their renormalizability follows from a "weighted power counting" criterion, which ensures that no higher time derivatives are generated by renormalization, despite the presence of higher space derivatives that improve the behaviours of propagators. Stability, the spectral representation, unitarity and causality are suitably generalized. The fixed points of the weighted RG flow are noticeable Lorentz violating generalizations of conformal field theories. Sigma and four-fermion fixed points that become renormalizable in the large N expansion are constructed. Solutions exist also in four and higher dimensions, even and odd. In some explicit four dimensional examples, I compute the correlation functions to the leading order in 1/N and the critical exponents to the subleading order. Possible applications to high energy physics are discussed.