Renormalization group and universality

Renormalization-group Theory and Universality along the Lambda Line Of

The present status of the renormalization-group (RG) predictions on the superfluid density ρ s and the specific heat C + and C − near the λ-line of 4 He is briefly reviewed. Particular attention is given to universal amplitude ratios related to these quantities. The goals of a new theory project are presented that involves higher-order calculations of the amplitude functions of ρ s , C + and C ...

Renormalization Group Renormalization Group

Time-Dependent Real-Space Renormalization Group Method

In this paper, using the tight-binding model, we extend the real-space renormalization group method to time-dependent Hamiltonians. We drive the time-dependent recursion relations for the renormalized tight-binding Hamiltonian by decimating selective sites of lattice iteratively. The formalism is then used for the calculation of the local density of electronic states for a one dimensional quant...

A NUMERICAL RENORMALIZATION GROUP APPROACH FOR AN ELECTRON-PHONON INTERACTION

A finite chain calculation in terms of Hubbard X-operators is explored by setting up a vibronic Harniltonian. The model conveniently transformed into a form so that in the case of strong coupling a numerical renormalization group approach is applicable. To test the technique, a one particle Green function is calculated for the model Harniltonian

Finite Size Scaling for the O(N) universality class from Renormalization Group Methods

The QCD phase diagram at finite temperature and density is a topic of considerable interest. Although much progress has been made in recent years, some open questions remain. Even at zero density, the order of the transition for two light flavors of fermions has not yet been conclusively established. While considerable evidence exists in favor of a second-order transition for massless quarks an...