Renormalization is a mathematical technique used in theoretical physics to account for infinities that arise in certain calculations. In the case of a non-renormalizable theory, these infinities cannot be eliminated completely, but they can be "renormalized" to produce finite, physically meaningful results.
Generally, a theory is considered non-renormalizable if it contains terms with higher powers of the energy or momentum than the theory's fundamental energy scale. This means that the theory cannot be accurately described at all energy scales, and a cutoff must be introduced to limit the calculations to a certain range.
Renormalization allows us to make predictions and calculations in non-renormalizable theories by accounting for the infinities that arise. While the theory may not be fully understood at all energy scales, renormalization allows us to make accurate predictions within a certain range.
Yes, there are limitations to renormalization. While it allows us to make predictions and calculations, it does not provide a complete understanding of the theory at all energy scales. Additionally, the cutoff introduced in renormalization can affect the accuracy of the results.
No, not all non-renormalizable theories can be renormalized. Some theories may be fundamentally flawed or inconsistent, and renormalization cannot fix these issues. In these cases, alternative theories must be proposed to accurately describe the phenomenon in question.