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SUMMARY:Topological strings and Siegel modular forms
DTSTART;VALUE=DATE-TIME:20150930T143500Z
DTEND;VALUE=DATE-TIME:20150930T145000Z
DTSTAMP;VALUE=DATE-TIME:20190916T165738Z
UID:indico-contribution-103@cern.ch
DESCRIPTION:Speakers: Mr. SCHIMANNEK\, Thorsten (University of Bonn)\nThe
topological string theory partition function captures non-trivial invarian
ts of Calabi-Yau threefolds. In general\, target space symmetries acting o
n the cohomology induce an automorphic structure on the free energies. For
non-compact geometries with spectral curve of genus one this allowed to r
e-express the physical constraints in terms of modular forms. The construc
tion\, however\, relied on a certain quasi modular object\, the second Eis
enstein series. We generalise this procedure to spectral curves of genus t
wo and show that the appropriate automorphic objects are Siegel modular fo
rms. In particular\, we propose an analogue for the second Eisenstein seri
es and a generalised Ramanujan identity both of which have not previously
been described in the mathematical literature.\nOn this class of geometrie
s we provide a straightforward recipe for solving the topological string.\
n\nhttps://indico.desy.de/indico/event/11875/session/4/contribution/103
LOCATION:DESY Hamburg Seminar room 1
URL:https://indico.desy.de/indico/event/11875/session/4/contribution/103
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