ultraviolet

Etymology

From ultra- + violet.

adj

1. Of electromagnetic radiation beyond (higher in frequency than) light visible to the human eye; radiation with wavelengths from 380 to 10 nanometres.
2. (figurative, physics) Relating to very high energies or very small distances or time spans.
   A one-loop Feynman graph that represents a virtual process. In the limit in which the virtual process involves short distances or high momenta, one may find an ultraviolet divergence in the corresponding amplitude. 2004, Barton Zwiebach, A First Course in String Theory, Figure 23.1, page 519
   Some have advocated the search for a new theory of quantum gravity, a theory which does not suffer from ultraviolet infinity problems. 2009, Herbert W. Hamber, Quantum Gravitation: The Feynman Path Integral Approach, page vii
   Since current gravitational observations are insensitive to quantum effects, one may wonder why an ultraviolet completion of the gravity theory is needed if inflation, in fact, occurs several orders of magnitude below the Planck scale. 2017, David F. Chernoff, S.-H. Henry Tye, “Inflation, string theory and cosmic strings”, in Wei-Tou Ni, editor, One Hundred Years of General Relativity[…], volume 2, page 275

noun

1. Ultraviolet colour.