How fast can it run? - Microscopic Bounds on Macroscopic Theories - 

08.11.2019 14:15 – 15:15

Effective Field Theories (EFTs) appear everywhere there is a mass scale.
They serve to simplify complex multiscale problems (e.g. the theory of fermions below the electroweak scale), and they
serve as general tools to parametrise the unknown or incalculable (e.g. the pion chiral Lagrangian, gravity, or physics
beyond the standard model). In this sense, they are perhaps even too general  (everything which is not forbidden is
compulsory).
In this talk I will present a tool to distinguish EFTs that can originate from microscopic unitary theories and I will show
that this strongly limits the (classic and quantum) running of EFTs scattering amplitudes. In particular, Massive gravity,
theories with isolated massive higher-spin particles, and theories with very irrelevant interactions, cannot originate from
unitary theories.

Lieu

Bâtiment: Ecole de Physique

Salle Stueckelberg

entrée libre