Four-loop renormalization with a cutoff in a sextic model

The quantum action for a three-dimensional real sextic model using the background field method is considered. Four-loop renormalization of this model is performed with a cutoff regularization in the coordinate representation. The coefficients for the renormalization constants are found, the applicability of the $\mathcal{R}$-operation within the proposed regularization is explicitly demonstrated, and the absence of nonlocal contributions is proved. Additionally, the explicit form of the singularities, power and logarithmic, as well as their dependence on the deformation of the Green’s function are discussed.