Multi-loop computations play a key role to obtain high-precision theoretical predictions.
The complexity of these computations involve the interplay of causal and non-causal
divergences. Naturally, non-causal singularities are not expected to appear in the final
result, and an algorithm performing these cancellations at integrand level is desired.
In this talk, a method to tackle multi-loop multi-leg scattering amplitudes called
Loop-Tree Duality is presented, together with its implications on the non-causal
divergences.