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advanced_notions:quantum_field_theory:gribov_ambiguities [2017/05/14 11:10]
jakobadmin
advanced_notions:quantum_field_theory:gribov_ambiguities [2017/11/05 15:34] (current)
jakobadmin ↷ Page moved from theories:gauge_theory:gribov_ambiguities to advanced_notions:quantum_field_theory:gribov_ambiguities
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 ====== Gribov Ambiguities ====== ====== Gribov Ambiguities ======
  
-It was proven by Singer in "Some Remarks on the Gribov Ambiguity"​ that "no continuous choice of exactly one +
-connection on each orbit can be made. Thus the Gribov ambiguity for the +
-Coloumb gauge will occur in all other gauges. No gauge fixing is possible. "+
  
 <tabbox Why is it interesting?> ​ <tabbox Why is it interesting?> ​
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   ​   ​
 <tabbox Student> ​ <tabbox Student> ​
 +
 +
  
 <​blockquote>​ <​blockquote>​
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 <tabbox Researcher> ​ <tabbox Researcher> ​
 +
 +<​blockquote>​
 +There is a difficulty which arises in the cornpactified
 +case which is not present in the more general one. This
 +involves gauge fixing and the Gribov ambiguity. ' As
 +yet the gauge has not been fixed and there is the possibility
 +that fixing the gauge could affect the topology of
 +configuration space. The object of gauge fixing is to
 +choose one member from each class of gauge-equivalent
 +configurations so that there will be no double counting
 +of configurations in the path integral.
 +In the fiber-bundle picture of Dowker, '
 +this corresponds
 +to finding a section in the bundle, reducing each
 +configuration fiber to a particular configuration in the fiber. The difficulty is that Singer'​ has proven that
 +there are no global gauges when space is compactified to
 +S . That is, there is no global section of the fiber bundle
 +that Dowker is using. This means that the space of
 +gauge-fixed configurations is disconnected. The answer is that the Gribov ambiguity allows for
 +certain zero-action discontinuous evolutions. Because
 +there are no global sections, the gauge fixing fails to always
 +specify a unique configuration from each
 +configuration fiber. When it does fail, there are two (or
 +more) configurations which are related by a gauge transformation.
 +Each of these lies on a different section of
 +the fiber bundle and one's histories may move between
 +the disconnected sections by way of these configurations.
 +
 +
 +<​cite>​Nontrivial homotopy and tunneling by topological instantons by Arlen Anderson</​cite>​
 +</​blockquote>​
 +
 +
 +It was proven by Singer in "Some Remarks on the Gribov Ambiguity",​ provided that we compactify spacetime to the 4-sphere, that <​q>"​no continuous choice of exactly one
 +connection on each orbit can be made. Thus the Gribov ambiguity for the
 +Coloumb gauge will occur in all other gauges. No gauge fixing is possible. "</​q>​
  
 <​blockquote>​ <​blockquote>​
advanced_notions/quantum_field_theory/gribov_ambiguities.1494753042.txt.gz · Last modified: 2017/12/04 08:01 (external edit)