UV Completion
From Wikipedia, the free encyclopedia
In theoretical physics, UV completion of a quantum field theory XY is another quantum field theory (or a more generalized theory) AB that reduces to XY below some energy scale (the cutoff of XY). However, AB must be, unlike XY, well-defined at arbitrarily high energies i.e. in the ultraviolet regime (this is the origin of the adjective "UV").
AB must be renormalizable; it can have no Landau poles; and most typically, AB enjoys asymptotic freedom in the case that AB is a quantum field theory (or at least has a nontrivial UV fixed point). However, AB may also be a background of string theory whose UV behavior is at least as good as that of renormalizable quantum field theories. Besides these two known examples (QFT and string theory), it could be a completely different theory than string theory that behaves well at very high energies, assuming that such a theory exists.
