@Qmechanic @DavidZ: I'm confused. One my flags for a res. rec. post was declined (by David, I think) with the reason "we don't make these CW anymore". But Qmechanic converted this res. rec. question into CW just now. What's going on?
@dmckee I also looked on meta, but I couldn't find a clear post whether the policy is to make them CW or not, just personal opinions with various votes.
I think there was something on the mother meta that mostly disowned the idea of imposing CW on posts as a policy decision. That is post should be either in or out, not in some wishy-washy middle ground where they are tolerated when CW.
@Danu Jaffe and Thruston....very intersting indeed ;-)
@Slereah In euclidean time you have a good number of rigorous results on path integrals (stochastic integrals); at least QM and low dimension QFT (interacting, for the free one there is not much problem)
for recent works (but the language is not so easy) see the fields medal Martin Hairer: arxiv.org/abs/1508.05261
@FreeMind I don't think there is much of a purpose anymore. At best, it's an indicator that a post is meant to be collaboratively edited - but since anyone can suggest edits anyway, it's just an indicator, it doesn't really enable a whole lot.
He just told me that indeed the collinear splitting is not forbidden by conservation laws, but by the gauge symmetry. I'm not sure he's thought about it deeper than "there's no 3-photon vertex for Abelian gauge theories".
@0celo7 "real reason" - for the collinear case, yes, but in all other cases, the conservation argument also forbids the splitting of non-Abelian massless gauge bosons.
Hi. I have to participate in a quiz this September on "Inventions and Discoveries in the field of Physics in the past 100 years". What topics should I focus on? Since it is a quiz, I think the Historical facts will be the basis.
I assume you know some algebra and calculus (@0B3 ;D)
@ambigram_maker (Don't let the comic sans like font fool you. It's an extremely hard book to read. Unless you have experience with differential geometry, point set topology and PDE theory, you won't be able to enjoy it.)
In the mathematical discipline of general topology, Stone–Čech compactification is a technique for constructing a universal map from a topological space X to a compact Hausdorff space βX. The Stone–Čech compactification βX of a topological space X is the largest compact Hausdorff space "generated" by X, in the sense that any map from X to a compact Hausdorff space factors through βX (in a unique way). If X is a Tychonoff space then the map from X to its image in βX is a homeomorphism, so X can be thought of as a (dense) subspace of βX. For general topological spaces X, the map from X to βX need...