2.1 dispersion relation
Here we compare the dispersion relation of the continuum E(p)2=m2+→p2 where pi=2πni/L, with the one on the lattice
coshE(p)=coshE(0)+123∑i=14sin2pi2. In terms of parameters of the lagrangian the dispersion relation looks like
coshE(p)=1+m2+123∑i=14sin2pi2. so E(0) is related to the parameter of the lagrangian m as
coshE(0)=1+m2