Critical exponents from the effective average action

Critical Exponents from the Effective Average Action

We compute the critical behaviour of three-dimensional scalar theories using a new exact non-perturbative evolution equation. Our values for the critical exponents agree well with previous precision estimates.

Critical exponents of the Gross-Neveu model from the effective average action.

The phase transition of the Gross-Neveu model with N fermions is investigated by means of a nonperturbative evolution equation for the scale dependence of the effective average action. The critical exponents and scaling amplitudes are calculated for various values of N in d = 3. It is also explicitly verified that the Neveu-Yukawa model belongs to the same universality class as the Gross-Neveu ...

Effective Critical Exponents from Finite Temperature Renormalization Group

Effective critical exponents for the λφ4 scalar field theory are calculated as a function of the renormalization group block size k−1 o and inverse critical temperature βc. Exact renormalization group equations are presented up to first order in the derivative expansion and numerical solutions are obtained with and without polynomial expansion of the blocked potential. For a finite temperature ...

Critical Equation of State from the Average Action.

The scaling form of the critical equation of state is computed for O(N)-symmetric models. We employ a method based on an exact flow equation for a coarse grained free energy. A suitable truncation is solved numerically.

Accurate critical exponents from the -expansion