Optimization of perturbative similarity renormalization group for Hamiltonians with asymptotic freedom and bound states

Abstract

A model Hamiltonian that exhibits asymptotic freedom and a bound state, is used to show on example that similarity renormalization group procedure can be tuned to improve convergence of perturbative derivation of effective Hamiltonians, through adjustment of the generator of the similarity transformation. The improvement is measured by comparing the eigenvalues of perturbatively calculated renormalized Hamiltonians that couple only a relatively small number of effective basis states, with the exact bound state energy in the model. The improved perturbative calculus leads to a few-percent accuracy in a systematic expansion.

6 pages of latex, 4 eps figures

References in corpus (5)

• Flow equations for band--matrices
• Asymptotic Freedom and Bound States in Hamiltonian Dynamics
• Dynamics of Effective Gluons
• Large-momentum convergence of Hamiltonian bound-state dynamics of effective fermions in quantum field theory
• Flow Equations for the Henon-Heiles Hamiltonian

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