Skip to main content
13 events
when toggle format what by license comment
Mar 2, 2010 at 16:45 answer added Tilman timeline score: 3
Mar 2, 2010 at 9:58 history edited Dmitri Pavlov
edited tags
Jan 31, 2010 at 22:51 answer added Tim Perutz timeline score: 6
Jan 31, 2010 at 22:44 answer added Dan Petersen timeline score: 5
Jan 31, 2010 at 21:58 answer added S. Carnahan timeline score: 3
Jan 31, 2010 at 21:33 answer added Ryan Budney timeline score: 6
Jan 31, 2010 at 21:13 history edited john mangual CC BY-SA 2.5
Added def'n of spin stricture. Corrected SU(2) to Spin(2)
Jan 31, 2010 at 20:52 comment added john mangual In the back of my head I was thinking the dimensions weren't right $Spin(2) = SO(2)$. Also, let me put in the specific definition of Spin structure from "Lectures on the Seiberg-Witten Invariants" by John Moore.
Jan 31, 2010 at 17:26 comment added Ryan Budney Start with getting a feel for all the various equivalent defininitions of orientation here: mathoverflow.net/questions/10966/… then you'll have a launching pad for thinking about spin structures. For example, one way to say a tangent bundle admits a spin structure is it is orientable and every map $S^2 \to M$ admits a lift $S^2 \to O(TM)$. See item (2) in my post to the linked thread. Also see the references below, and the text by Milnor and Stasheff.
Jan 31, 2010 at 8:47 comment added Anirbit Probably a very naive question in the context of this thread but still probably not fully out of context to request for detailed expositions on spin structures. Can you give references which will teach in details the whole idea of spin bundles and spin connections and spinors?
Jan 30, 2010 at 21:26 answer added José Figueroa-O'Farrill timeline score: 5
Jan 30, 2010 at 21:20 comment added Ryan Budney There aren't any representations of $SU(2)$ on $T_pE$, as $SU(2)$ is a 3-dimensional compact Lie group, in particular it doesn't have any connected normal subgroups. Spin structures have many formulations, what flavour are you looking for? Usually you start by taking the direct sum of the tangent bundle with a trivial line bundle, when you're dealing with 2-dimensional vector bundles.
Jan 30, 2010 at 21:10 history asked john mangual CC BY-SA 2.5