renormalised

Renormalised is the British spelling of renormalized and acts as an adjective describing quantities that have undergone renormalization. Renormalization is a systematic procedure used in theoretical physics and applied mathematics to redefine parameters in a model so that predictions remain finite and physically meaningful, often by absorbing divergences or scale dependencies into new, measurable quantities.

In quantum field theory, renormalised parameters such as the renormalised mass and renormalised charge arise after absorbing infinities into renormalisation constants. The resulting values depend on a chosen energy scale, known as the renormalisation scale, and on a particular renormalisation scheme. Despite scheme or scale dependence of intermediate quantities, physical observables are finite and consistently calculable when the renormalisation program is applied correctly.

In statistical physics and the study of critical phenomena, renormalisation describes how system properties change with length scale. Coarse-graining leads to renormalised couplings that flow under the renormalisation group. The behavior near fixed points determines universal properties like critical exponents, independent of microscopic details.

Renormalised quantities are commonly encountered in discussions of renormalised mass, renormalised coupling constants, or renormalised fields. The concept emphasizes that the parameters used in a theory reflect measurable quantities rather than unphysical bare values. Care is required because results can depend on the chosen renormalisation scheme and scale, though correctly defined observables remain invariant.

See also: renormalization, renormalisation group, quantum field theory.