Renormalisaatioteoreema

Renormalisaatioteoreema, known in English as the renormalization theorem, is a fundamental concept in quantum field theory (QFT) that addresses the issue of infinities arising in calculated quantities. During the process of quantizing fields and calculating particle interactions, divergent integrals often appear, leading to infinite results that are physically meaningless. The renormalization theorem provides a systematic method to handle these infinities, allowing for the extraction of finite, measurable predictions.

The core idea of the renormalizaatioteoreema is that the infinities encountered in calculations can be absorbed into redefined or "renormalized" parameters, such as particle masses and coupling constants. This redefinition involves introducing counterterms in the theory's Lagrangian, which cancels out the divergences in the original computations. As a result, the physical predictions become independent of the arbitrary high-energy or short-distance cutoff used during regularization.

Developed in the mid-20th century through work by physicists like Gerard 't Hooft and Martinus Veltman, the renormalization theorem was a critical step in establishing the consistency and predictive power of quantum electrodynamics (QED) and later other gauge theories, such as the Standard Model. It demonstrated that a wide class of quantum field theories are renormalizable, meaning their infinities can be systematically managed.

Overall, the renormalisaatioteoreema has been instrumental in formalizing how infinities are treated within theoretical physics, enabling precise experimental predictions and advancing our understanding of fundamental particles and interactions.