From: Steve Carlip <carlip@dirac.ucdavis.edu>
Subject: Re: Clifford Algebras
Date: 7 Nov 2000 21:24:42 GMT
Newsgroups: sci.physics.research
Summary: [missing]

John Baez <baez@galaxy.ucr.edu> wrote:

> Once upon a time, Cecile DeWitt-Morette and her husband 
> Bryce DeWitt were doing a physics calculation and got different
> answers because they were using metrics of different sign: +--- 
> versus +++-.  She found this so amazing that she wound up
> giving talks about it all over the place.  I was lucky enough to
> attend one of these talks.  Perhaps she also wrote a paper about
> this topic.  

Yes, she and I did:
 
S. Carlip and C. DeWitt-Morette, ``Where the Sign of the Metric 
Makes a Difference,''  Phys. Rev. Lett. 60 (1988) 1599.

She and Bryce also wrote a paper with some computations that
showed the difference explicitly:

C. DeWitt-Morette and B.S. DeWitt, ``Pin groups in physics,''
Phys. Rev. D41 (1990) 1901.

Steve Carlip