unrenormalized

Unrenormalized refers to a theoretical concept, primarily used in quantum field theory, to describe quantities or calculations that have not undergone the process of renormalization. Renormalization is a technique used to handle infinities that arise in calculations of physical quantities in quantum field theories. These infinities, often referred to as divergences, appear when considering interactions at very short distances or very high energies.

An unrenormalized quantity is essentially a raw result from a calculation before these infinities have been systematically removed or absorbed into a redefinition of physical parameters. For example, in quantum electrodynamics, the unrenormalized mass or charge of an electron would include contributions from virtual particle loops that lead to infinite values. The process of renormalization involves introducing counterterms that cancel these infinities, leading to finite and physically observable values for quantities like the electron's mass and charge.

Therefore, an unrenormalized calculation is considered incomplete or non-physical in its raw form. It represents an intermediate step in a theoretical framework, awaiting the application of renormalization procedures to yield meaningful predictions that can be compared with experimental data. The concept highlights the limitations of naive perturbative expansions in quantum field theory and the necessity of renormalization to make these theories consistent and predictive.