- Gribov ambiguity
In gauge theory, especially non-abelian gauge theories, we often encounter
global problems whengauge fixing . Gauge fixing means choosing a representative from eachgauge orbit . The space of representatives is a submanifold and represents the gauge fixing condition. Ideally, every gauge orbit will intersect this submanifold once and only once. Unfortunately, this is often impossible globally for non-abelian gauge theories because of topological obstructions and the best that can be done is make this condition true locally. A gauge fixing submanifold may not intersect a gauge orbit at all or it may intersect it more than once. This is called a Gribov ambiguity.Gribov ambiguities lead to a
nonperturbative failure of theBRST symmetry, among other things.
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