Sunday, 1 November 2009

ag.algebraic geometry - References for Donaldson-Thomas theory and Pandharipande-Thomas theory?

I would be very happy if such material existed!!!



But just to statisfy the first curiosity,
There is a 1 hour lecture of Richard Thomas online on MSRI



Counting curves in 3-folds, 2009



http://www.msri.org/communications/vmath/VMathVideos/VideoInfo/4118/show_video



I would like to add just one little thing that I know about DT and find cool. Consider a 3-dimensional CY manifold X with a holomorphic volume form $W$.



Statement. On the space of smooth 2-dimesnional surfaces in X there is a natural (possibly multi-valued) functional F, defined by $W$. Moreover, holomorphic curves in X are exactly the critical points of the functional.



Definition of the functional. Take a surface S, and define F(S)=0, for any other surface $S_1$ homological to S consider a 3-manifold M whose boundary is $S-S_1$. Integrate W over M. This gives the value of F at $S_1$.



In is not hard to check that holomorphic curves are critical points of F, so couniting holomorphic curves in a CY 3-fold can be seen as finding the number of critical points of a functional.

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