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X-WR-CALNAME:Yanki Lekili: \"Wrinkled fibrations on near-symplectic mani
 folds\"
PRODID:-//Apple Computer\, Inc//iCal 2.0//EN
CALSCALE:GREGORIAN
METHOD:PUBLISH
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TZID:America/New_York
LAST-MODIFIED:20080415T200325Z
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DTSTART:20080309T070000
TZOFFSETTO:-0400
TZOFFSETFROM:+0000
TZNAME:EDT
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BEGIN:VEVENT
DURATION:PT1H
LOCATION:Math 520\, Columbia University
DTSTAMP:20080415T200322Z
UID:EC68321A-34AD-40AA-B0E5-102A3A4782D0
SEQUENCE:10
URL;VALUE=URI:http://math.columbia.edu/~lipshitz/SGGT/
DTSTART;TZID=America/New_York:20080425T130000
SUMMARY:Yanki Lekili: \"Wrinkled fibrations on near-symplectic manifolds
 \"
DESCRIPTION:Abstract : Motivated by the programmes initiated by Taubes a
 nd Perutz\, we study the geometry of near-symplectic 4-manifolds and bro
 ken Lefschetz fibrations on them. We present a set of four moves which a
 llow us to pass from any given fibration to any other broken fibration w
 hich is deformation equivalent to it. The arguments rely on the introduc
 tion of a more general class of maps\, which we call wrinkled fibrations
  and which allow us to rely on classical singularity theory. As an appli
 cation\, we disprove a conjecture of Gay and Kirby about essentialness o
 f achiral singularities for broken fibrations on arbitrary closed 4-mani
 folds.
ORGANIZER;CN="Robert Lipshitz":mailto:lipshitz@math.stanford.edu
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