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SUMMARY:Nikolas Kuhn (Stanford University)
DTSTART;VALUE=DATE-TIME:20210326T190000Z
DTEND;VALUE=DATE-TIME:20210326T200000Z
DTSTAMP;VALUE=DATE-TIME:20210926T124101Z
UID:agstanford/44
DESCRIPTION:Title: A blowup formula for virtual Donaldson invariants\nby Nikolas Kuhn
(Stanford University) as part of Stanford algebraic geometry seminar\n\n\
nAbstract\nDonaldson invariants were a breakthrough in the study of smooth
four-manifolds when they were introduced in the 1980s and even found appl
ications to the classification of compact complex surfaces. With the adven
t of the virtual fundamental class\, it has become possible to give an ele
gant purely algebraic definition when working on a complex projective surf
ace X\, which was done by T. Mochizuki. The two definitions agree in most
cases\, and whether they agree in general comes down to knowing a blowup f
ormula for Mochizuki's invariants. We present a direct proof of such a blo
wup formula that generalizes earlier results by Göttsche-Nakajima-Yoshiok
a and has applications to other types of enumerative invariants of X. This
is joint work with Yuuji Tanaka.\n\nThe discussion for Nikolas Kuhn’s t
alk is taking place not in zoom-chat\, but at https://tinyurl.com/2021-03-
26-nk (and will be deleted after ~3-7 days).\n
LOCATION:https://researchseminars.org/talk/agstanford/44/
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