In this talk, I try to explain the recent progress and my interest in the Lattice QCD and tensor renormalization group in the context of the numerical calculation of perturbative quantities.
We can calculate perturbative quantities such as the quark mass and the strong coupling constant by using the high-order perturbative expansion of moments or Dirac spectral density.
I’ll show you some essence of these calculations, especially for the systematic error from the fermion formulation.
On the tensor renormalization group, we can demonstrate that there is no sampling problem by considering the perturbative quantities.
I also try to mention that the recent progress on network construction and contraction.
The numerical cost is drastically reduced by the combination of the SVD.