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1. • CommentRowNumber1.
   • CommentAuthorUrs
   • CommentTimeJul 10th 2012
   • PermaLink
   Author: Urs
   Format: MarkdownItexstub for _[[metaplectic group]]_

   stub for metaplectic group

2. • CommentRowNumber2.
   • CommentAuthorUrs
   • CommentTimeJan 1st 2015
   • PermaLink
   Author: Urs
   Format: MarkdownItexadded to _[[metaplecitc group]]_ the definition of $Mp^c$ ([here](http://ncatlab.org/nlab/show/metaplectic+group#CircleExtension)), a $U(1)$-extension of the symplectic group. Hm, given a symplectic vector space there is also the restriction of the [[quantomorphims group]] to linear symplectomorphisms, which also gives a $U(1)$-extension of the symplectic group. Is this $Mp^c$?

   added to metaplecitc group the definition of $Mp^c$ (here), a $U(1)$-extension of the symplectic group.

   Hm, given a symplectic vector space there is also the restriction of the quantomorphims group to linear symplectomorphisms, which also gives a $U(1)$-extension of the symplectic group. Is this $Mp^c$?

3. • CommentRowNumber3.
   • CommentAuthorUrs
   • CommentTimeJan 1st 2015
   • PermaLink
   Author: Urs
   Format: MarkdownItexThat other $U(1)$-extension that I mean is called the "extended symplectic group" in section 9 of [Robbin-Salamon 93](http://ncatlab.org/nlab/show/quantomorphism+group#RobbinSalamon93). Their prop. 10.1 goes in the direction of the above question.

   That other $U(1)$-extension that I mean is called the “extended symplectic group” in section 9 of Robbin-Salamon 93. Their prop. 10.1 goes in the direction of the above question.

4. • CommentRowNumber4.
   • CommentAuthorUrs
   • CommentTimeJan 2nd 2015
   • PermaLink
   Author: Urs
   Format: MarkdownItexI have expanded a litte bit more at _[[metaplectic group]]_; added a bit more on the various definitions, and added more pointers to the literature.

   I have expanded a litte bit more at metaplectic group; added a bit more on the various definitions, and added more pointers to the literature.

5. • CommentRowNumber5.
   • CommentAuthorDavid_Corfield
   • CommentTimeJan 2nd 2015
   • PermaLink
   Author: David_Corfield
   Format: MarkdownItexIs this fact from [Wikipedia](http://en.wikipedia.org/wiki/Metaplectic_group) worth developing here? >The metaplectic group has a particularly significant infinite-dimensional linear representation, the Weil representation. It was used by André Weil to give a representation-theoretic interpretation of theta functions, and is important in the theory of modular forms of half-integral weight and the theta correspondence.

   Is this fact from Wikipedia worth developing here?

   The metaplectic group has a particularly significant infinite-dimensional linear representation, the Weil representation. It was used by André Weil to give a representation-theoretic interpretation of theta functions, and is important in the theory of modular forms of half-integral weight and the theta correspondence.

6. • CommentRowNumber6.
   • CommentAuthorUrs
   • CommentTimeJan 2nd 2015
   • PermaLink
   Author: Urs
   Format: MarkdownItexYes, that's a good point. There are some comments on the on the $n$Lab at _[metaplectic correction -- Induced inner product](http://ncatlab.org/nlab/show/metaplectic+correction+%28in+geometric+quantization%29#InducedInnerProduct)_, but maybe this deserves to be expanded further.

   Yes, that’s a good point. There are some comments on the on the $n$Lab at metaplectic correction – Induced inner product, but maybe this deserves to be expanded further.

7. • CommentRowNumber7.
   • CommentAuthorUrs
   • CommentTimeJan 2nd 2015
   • PermaLink
   Author: Urs
   Format: MarkdownItexAdded also $MU^c$ (somewhat unforturnate notation...) [here](http://ncatlab.org/nlab/show/metaplectic+group#CirclExtensionMUc) and the induced obstruction theory for $Mp^c$-structure [here](http://ncatlab.org/nlab/show/metaplectic+group#NonTrivialityOfExtensions).

   Added also $MU^c$ (somewhat unforturnate notation…) here and the induced obstruction theory for $Mp^c$-structure here.