Editing Ultraviolet divergence (section)

==Overview==
Since an infinite result is unphysical, ultraviolet divergences often require special treatment to remove unphysical effects inherent in the perturbative formalisms. In particular, UV divergences can often be removed by [[regularization (physics)|regularization]] and [[renormalization]]. Successful resolution of an ultraviolet divergence is known as '''[[UV completion|ultraviolet completion]]'''. If they cannot be removed, they imply that the theory is not [[perturbative]]ly well-defined at very short distances.

The name comes from the earliest example of such a divergence, the "[[ultraviolet catastrophe]]" first encountered in understanding [[blackbody radiation]]. According to [[classical physics]] at the end of the nineteenth century, the quantity of [[radiation]] in the form of [[light]] released at any specific [[wavelength]] should increase with decreasing wavelength—in particular, there should be considerably more [[ultraviolet light]] released from a blackbody radiator than [[infrared light]]. Measurements showed the opposite, with maximal energy released at intermediate wavelengths, suggesting a failure of [[classical mechanics]]. This problem eventually led to the development of [[quantum mechanics]].

The successful [[Ultraviolet_catastrophe#Solution|resolution]] of the original ultraviolet catastrophe has prompted the pursuit of solutions to other problems of ultraviolet divergence. A similar problem in [[electromagnetism]] was solved by [[Richard Feynman]] by applying [[quantum field theory]] through the use of [[renormalization]], leading to the successful creation of [[quantum electrodynamics]] (QED). Similar techniques led to the [[standard model]] of [[particle physics]]. Ultraviolet divergences remain a key feature in the exploration of new physical theories, like [[supersymmetry]].