Renormieren

Renormieren is a technique used in quantum field theory to handle infinities that arise in calculations. These infinities appear when one tries to compute physical quantities, such as the mass or charge of a particle, by considering interactions at all possible energy scales. The process of renormierung essentially redefines the fundamental parameters of the theory, such as the bare mass and bare charge, in terms of physical, observable quantities.

The core idea is that the "bare" parameters, which are the values that appear in the initial formulation of the theory, are not directly measurable. Instead, the measurable quantities are "dressed" by the effects of virtual particles that are constantly being created and destroyed in the quantum vacuum. Renormierung provides a systematic way to absorb the infinite contributions from these virtual particle loops into the definitions of the physical parameters.

This process allows physicists to make finite and predictive calculations, despite the presence of infinities. The success of the Standard Model of particle physics, for instance, relies heavily on the renormierung procedure. It is a crucial tool for making theoretical predictions that can be compared with experimental results. Different physical theories may require different renormierung schemes, but the underlying principle of absorbing infinities into redefined parameters remains the same.