Renormalization of the energy momentum tensor in lattice field theory.

The Energy Momentum Tensor is a fundamental quantity for a quantum field theory.
It generates the Noether current of the Poincare symmetry and its trace probes the properties
of the renormalization group flow of the theory. In the continuum formulation its
renormalization is constrained by the translation Ward identities; however on the lattice it
renormalizes in a more complicated way, indeed translational symmetry is explicitly broken by
the lattice regulators. I will discuss a technique to renormalize the Energy Momentum Tensor
non-perturbatively on the lattice and I will present some preliminary results for the 3d scalar field
theory.