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View Full Version : grothendieck decompostion simple example


Jim Kata
Jul30-11, 03:42 AM
Say you have exp{(\omega)} and \omega has a simple pole show that
exp{(\omega)}=exp{(F+)}z^{-1}exp{(F-)} where F+ is holomorphic and F- is antiholomorphic. My basic thought is if \omega has a simple pole then \omega z is holomorphic and on the punctured disk it can be represented by a Laurant series. The problem is that I'm missing a factor of log on z.

bpet
Aug10-11, 08:32 PM
That can't be right - consider w=1/z, so exp(w) has an essential singularity at z=0 and thus hits almost every value in a neighbourhood of 0. But if F+ and F- are holomorphic and antiholomorphic then exp(F+) and exp(F-) would be close to 1 near z=0, which means that |exp(F+)*exp(F-)/z| is bounded from below near z=0.