Discovery
Asymptotic freedom was discovered in 1973 by David Gross and Frank Wilczek, and by David Politzer. Although these authors were the first to understand the physical relevance to the strong interactions, in 1969 Iosif Khriplovich discovered asymptotic freedom in the SU(2) gauge theory as a mathematical curiosity, and Gerardus 't Hooft in 1972 also noted the effect but did not publish. For their discovery, Gross, Wilczek and Politzer were awarded the Nobel Prize in Physics in 2004.
The discovery was instrumental in rehabilitating quantum field theory. Prior to 1973, many theorists suspected that field theory was fundamentally inconsistent because the interactions become infinitely strong at short distances. This phenomenon is usually called a Landau pole, and it defines the smallest length scale that a theory can describe. This problem was discovered in field theories of interacting scalars and spinors, including quantum electrodynamics, and Lehman positivity led many to suspect that it is unavoidable. Asymptotically free theories become weak at short distances, there is no Landau pole, and these quantum field theories are believed to be completely consistent down to any length scale.
While the Standard Model is not entirely asymptotically free, in practice the Landau pole can only be a problem when thinking about the strong interactions. The other interactions are so weak that any inconsistency can only arise at distances shorter than the Planck length, where a field theory description is inadequate anyway.
Read more about this topic: Asymptotic Freedom
Famous quotes containing the word discovery:
“That the discovery of this great truth, which lies so near and obvious to the mind, should be attained to by the reason of so very few, is a sad instance of the stupidity and inattention of men, who, though they are surrounded with such clear manifestations of the Deity, are yet so little affected by them, that they seem as it were blinded with excess of light.”
—George Berkeley (1685–1753)
“Next to the striking of fire and the discovery of the wheel, the greatest triumph of what we call civilization was the domestication of the human male.”
—Max Lerner (b. 1902)
“The discovery of Pennsylvania’s coal and iron was the deathblow to Allaire. The works were moved to Pennsylvania so hurriedly that for years pianos and the larger pieces of furniture stood in the deserted houses.”
—For the State of New Jersey, U.S. public relief program (1935-1943)