Vladimir Gribov

From Wikipedia, the free encyclopedia

This article does not cite any references or sources. (April 2008)
Please help improve this article by adding citations to reliable sources. Unverifiable material may be challenged and removed.

Vladimir Gribov was an influential Soviet theoretical physicist, known for his many contributions to the theory of the strong interactions.

In the late 1950s and early 1960s, Gribov recognized an inconsistency in the then popular model of the strongly interacting particles as diffracting black-disks, and replaced this hypothesis with the pomeron, a description of maximum possible interaction which is relativistically consistent. He went on to formulate the Reggeon Field Theory, a perturbative framework for analyzing reggeon exchange ^[1].

In quantum field theory, Gribov was instrumental in understanding how Regge behavior emerges from field theories which are described by point-particles. He extended the Feynman parton model to give a qualitative description of the Pomeron as a diffusive process, while close collaborators went on to formulate a perturbative description of the closely related hard Pomeron within QCD.

Gribov was the first to note that covariant gauge fixing in a non-abelian gauge theory leaves a large amount of gauge freedom unfixed, which separates the Gauge field phase space into oddly shaped regions called Gribov copies which have the property that it is difficult to stay in any one copy while randomly walking around field space. Gribov noted that this is crucial for gluon confinement, since a mass gap precisely means that the field fluctuations are of a bounded size. This insight played a crucial role in Feynman's semi-quantitative explanation for the confinement phenomenon in 2+1 dimensional nonabelian gauge theory, a method which was recently extended by Karbali and Nair into a fully quantitative description of the 2+1 dimensional nonabelian gauge vacuum.

In his last years, Gribov was attempting to construct a theory for quark confinement based on a rough analogy to the electromagnetic phenomenon of maximum nuclear charge.