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SUMMARY:M-theory on nodal Calabi-Yau 3-folds and torsion refined GV-invari
 ants
DTSTART:20231121T130000Z
DTEND:20231121T150000Z
DTSTAMP:20260827T212000Z
UID:indico-event-462@indico.hiskp.uni-bonn.de
DESCRIPTION:Speakers: Thorsten Schimannek (Utrecht University)\n\nIn this 
 talk we will argue that the physics of M-theory and Type IIA strings on no
 dal CY 3-folds is essentially determined by the geometry of a small resolu
 tion\, even if the latter is not Kähler.We will demonstrate this explicit
 ly in the context of nodal CY 3-folds that are double covers of P^3 with t
 he ramification locus being a symmetric determinantal surface.Using conifo
 ld transitions\, we prove that in certain cases the exceptional curves in 
 any small resolution are torsion while the same transitions imply that M-t
 heory develops a discrete gauge symmetry.We further argue that twisted cir
 cle compactifications of the 5d theory are dual to IIA compactifications o
 n the nodal CY 3-fold with a flat but topologically non-trivial B-field.Gi
 ven knowledge of the A-model topological string free energies associated t
 o all twists one can then extract the torsion refined GV-invariants.In man
 y cases GLSM techniques and/or mirror symmetry can be used to calculate th
 ese topological string free energies at least for low genera.\n\nhttps://i
 ndico.hiskp.uni-bonn.de/event/462/
URL:https://indico.hiskp.uni-bonn.de/event/462/
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