• Nonperturbative flow equations from running expectation values 

      Scholtz, F. G.; Bartlett, Bruce H.; Geyer, H. B. (American Physical Society (APS), 2003-08)
      We show that Wegner’s flow equations, as recently discussed in the Lipkin model, can be solved selfconsistently. This leads to a nonlinear differential equation which fully determines the order parameter as a function ...