Radiative corrections are an essential ingredient in precision physics, and are necessary in most colliders, including LHC. However, their calculation is often plagued with infinities that challenge theoreticians and our intuition.
In this seminar, I will explain the origin of such corrections as well as how infinities force us to change our classic conception of fundamental parameters such as the electric charge. The necessary ingredients to get then a finite result for a given process will be outlined in a simple way.