I was thinking it must have been a Phi
(
Moon Girl Technologies horrendous beanbag,
Thu 5 Nov 2009, 16:45,
archived)
I was going to make it but that actually makes even less sense. This way he's saying it's the S matrix of the stress-energy tensor. Which makes no sense either, but perhaps a bit more...
(
boris the spider,
Thu 5 Nov 2009, 17:16,
archived)