Safety versus triviality on the lattice

Understand

We present the first numerical study of the ultraviolet dynamics of non-asymptotically free gauge-fermion theories at large number of matter fields.

• As testbed theories we consider non-abelian SU(2) gauge theories with 24 and 48 Dirac fermions on the lattice.
• For these number of flavors asymptotic freedom is lost and the theories are governed by a gaussian fixed point at low energies.
• In the ultraviolet they can develop a physical cutoff and therefore be trivial, or achieve an interacting safe fixed point and therefore be fundamental at all energy scales.