We have a pleasure to invite you the Particle Theory Seminar on
WEDNESDAY (exceptional change of day), May 19, 2021 at 12:15
Prof. Stanisław Głazek (University of Warsaw)
Elementary example of exact effective-Hamiltonian computation
We present an exact computation of effective Hamiltonians for an elementary model obtained from the Yukawa theory by going to the limit of bare fermions being infinitely heavy and bare bosons being at rest with respect to the fermions that emit or absorb them. The coupling constant can be arbitrarily large. The Hamiltonians are computed by solving the differential equation of the renormalization group procedure for effective particles (RGPEP). Physical fermions, defined in the model as eigenstates of the effective Hamiltonians, are obtained in the form of an effective fermion dressed with a coherent state of effective bosons. The model computation illustrates the method that can be used in perturbative computations of effective Hamiltonians for realistic theories. It shows the mechanism by which the perturbative expansion and Tamm-Dancoff approximation increase in accuracy along the RGPEP evolution.
Seminar will take place on the Zoom platform (coordinates upon request by email).