renormalisatie

Renormalisatie, or renormalization in English, is a mathematical and conceptual framework primarily used in quantum field theory and statistical physics. It addresses the problem of infinities that arise in calculations involving interactions at very small scales or high energies. The core idea of renormalization is to redefine certain parameters within a theory—such as mass, charge, or coupling constants—in a way that absorbs these infinities, resulting in finite, physically meaningful predictions.

The development of renormalization techniques began in the mid-20th century, notably through the work of physicists such as Richard Feynman, Julian Schwinger, and Sin-Itiro Tomonaga. It proved crucial in making sense of quantum electrodynamics (QED), leading to highly accurate predictions that matched experimental results.

Renormalization involves the systematic process of introducing counterterms into a theory's equations to cancel infinities and then adjusting the parameters (renormalized parameters) to correspond with observable quantities. This process also typically involves the use of scale-dependent functions, known as renormalization group equations, which describe how physical parameters change with energy scale. These concepts have significance beyond particle physics, notably in condensed matter physics, where they explain phenomena such as phase transitions and critical points.

Despite its success and widespread application, renormalization remains a conceptually challenging topic, as it highlights how physical laws can change depending on the scale at which they are examined. Its development has significantly advanced the understanding of fundamental interactions and critical phenomena, reflecting its importance across various fields of physics.