Recent content by David Corfield

The error message is supposed to indicate the problem, but I can't see what it's objecting to: <math xmlns="http://www.w3.org/1998/Math/MathML" display="block"> <merror> <mtext>\label{OnRegularObservablesQuantumMasterWardIdentityViaTimeOrdered}&#xA0...

Now you've told me about the spectral triple modelling all particles at once as a composite system, that shifts the thought I was vaguely pointing to towards something like: Does the 2d SCFT of a spinning string contain within it all particles in a more structured way than as the spectral...

Oh, and more typos: of quantum some particle; supersymmtry algebra; dimenion; do not come describe

"Effective spacetime geometry seen by a quantum particle" From this point of view, we would presumably expect then different kinds of particles to see different geometries. If so, can those geometries be made compatible? "In the limit where the string’s oscillations are in their quantum...

Is there formatting advice somewhere? "In section 1.3 of Roggenkamp-Wendland 03 they discuss how to extract commutative spectral (pre-)triples from a CFT, calling them "commutative sub-geometries"." I went looking to see if there is something Bohr topos-like...

"The bouquet which emanates form these..." should be FROM. Also various pieces of latex didn't compile. Have you seen any other interesting bouquets? What would happen in the complex analytic world? I see there is some gauge theoretic interest in complex analytic superspaces...

"More generally one need jet bundles of more general arithmetic bundles." Is he as limited as this? In 'Differential calculus with integers' (http://arxiv.org/abs/1308.5194) he's talking about taking jet spaces of spec(W(R)) (p-typical Witt vectors of R) in section 1.2.12. And problem...

Thanks. I see Anderson has a G-equivariant version for some group of symmetries of E, which delivers a G-invariant Euler-Lagrange complex. He paints a picture of an ambitious research program. Would it be fair to say this work hasn't been exploited by the community as much as it might have been?

There are some (three?) occasions where the Latex didn't compile. And some typos: bunle; invariace; codimenion; depening This post will need some re-reading on my part. I wonder how much these constructions are arising through abstract general considerations. E.g. where one to want such a...

I see the Anderson you mentioned above has moved into computer techniques for differential geometry. That might provide a point of comparison if you succeed in encouraging people to implement modal homotopy type theory.

That's helpful, thanks. Returning to Butterfield's text, regarding his modality type 2, " it considers a counterfactual number of degrees of freedom, or a counterfactual potential function," wouldn't that include varying the Lagrangian, which you have above as type 3? His 3rd type, as I...

So we could do with an nLab entry on 'shell'. At the moment we just have "off-shell Poisson bracket' and ''on-shell recursion'. You're saying the shell is the critical locus of the EL-functional. Hmm, I see there are some basics I haven't sorted out. Why doesn't the process of finding the...

One day I mean to take another look at http://arxiv.org/abs/physics/0210081 to see whether the modality of classical mechanics there matches your ideas.