Algebraic Computation of the Hierarchical Renormalization Group Fixed   Points and their $\epsilon$-Expansions
  Nontrivial fixed points of the hierarchical renormalization group are computed by numerically solving a system of quadratic equations for the coupling constants. This approach avoids a fine tuning of relevant parameters. We study the eigenvalues of the renormalization group transformation, linearized around the non-trivial fixed points. The numerical results are compared with $\epsilon$-expansion. 
K. Pinn, A. Pordt, and C. Wieczerkowski