Continuum Scaling from Large Mass Expansion on the Lattice: Delta   Expansion Applied to the Anharmonic Oscillator
  We dilate the scaling region of the lattice anharmonic oscillator at strong coupling by introducing the parameter delta. Performing expansion in delta, the calculation of the mass gap in the continuum limit via the series expansion effective at large lattice spacings is then studied. We show that the dilation on the mass parameter M recovers the scaling behavior of the hopping parameter beta and allows for precise approximation of the mass gap. 
Hideko Hashiguchi, Keisuke Hoshino, Hirofumi Yamada