41 research outputs found
Strongly Fillable Contact Manifolds and J-holomorphic Foliations
We prove that every strong symplectic filling of a planar contact manifold
admits a symplectic Lefschetz fibration over the disk, and every strong filling
of the 3-torus similarly admits a Lefschetz fibration over the annulus. It
follows that strongly fillable planar contact structures are also Stein
fillable, and all strong fillings of the 3-torus are equivalent up to
symplectic deformation and blowup. These constructions result from a
compactness theorem for punctured J-holomorphic curves that foliate a convex
symplectic manifold. We use it also to show that the compactly supported
symplectomorphism group on the cotangent bundle of the 2-torus is contractible,
and to define an obstruction to strong fillability that yields a
non-gauge-theoretic proof of Gay's recent nonfillability result for contact
manifolds with positive Giroux torsion.Comment: 44 pages, 2 figures; v.3 has a few significant improvements to the
main results: We now classify all strong fillings and exact fillings of T^3
(without assuming Stein), and also show that a planar contact manifold is
strongly fillable if and only if all its planar open books have monodromy
generated by right-handed Dehn twists. To appear in Duke Math.
Holomorphic Curves in Blown Up Open Books
We use contact fiber sums of open book decompositions to define an infinite
hierarchy of filling obstructions for contact 3-manifolds, called planar
k-torsion for nonnegative integers k, all of which cause the contact invariant
in Embedded Contact Homology to vanish. Planar 0-torsion is equivalent to
overtwistedness, while every contact manifold with Giroux torsion also has
planar 1-torsion, and we give examples of contact manifolds that have planar
k-torsion for any but no Giroux torsion, leading to many new examples
of nonfillable contact manifolds. We show also that the complement of the
binding of a supporting open book never has planar torsion. The technical basis
of these results is an existence and uniqueness theorem for J-holomorphic
curves with positive ends approaching the (possibly blown up) binding of an
ensemble of open book decompositions.Comment: This preprint is now superseded by the paper "A Hierarchy of Local
Symplectic Filling Obstructions for Contact 3-Manifolds", arXiv:1009.274
Contact 3-manifolds, holomorphic curves and intersection theory
This is a revision of some expository lecture notes written originally for a
5-hour minicourse on the intersection theory of punctured holomorphic curves
and its applications in 3-dimensional contact topology. The main lectures are
aimed primarily at students and require only a minimal background in
holomorphic curve theory, as the emphasis is on topological rather than
analytical issues. Some of the gaps in the analysis are then filled in by the
appendices, which include self-contained proofs of the similarity principle and
positivity of intersections, and conclude with a "quick reference" for the
benefit of researchers, detailing the basic facts of Siefring's intersection
theory.Comment: 170 pages, 20 figures; v2 is an extensive revision, with a new
introduction and expanded appendices (including a self-contained proof of
positivity of intersections, new material on intersection products of
holomorphic buildings, and a comparison of conventions with the ECH
literature). To appear as a book in the Cambridge Tracts in Mathematics
series with Cambridge University Pres
Algebraic Torsion in Contact Manifolds
We extract a nonnegative integer-valued invariant, which we call the "order
of algebraic torsion", from the Symplectic Field Theory of a closed contact
manifold, and show that its finiteness gives obstructions to the existence of
symplectic fillings and exact symplectic cobordisms. A contact manifold has
algebraic torsion of order zero if and only if it is algebraically overtwisted
(i.e. has trivial contact homology), and any contact 3-manifold with positive
Giroux torsion has algebraic torsion of order one (though the converse is not
true). We also construct examples for each nonnegative k of contact 3-manifolds
that have algebraic torsion of order k but not k - 1, and derive consequences
for contact surgeries on such manifolds. The appendix by Michael Hutchings
gives an alternative proof of our cobordism obstructions in dimension three
using a refinement of the contact invariant in Embedded Contact Homology.Comment: 53 pages, 4 figures, with an appendix by Michael Hutchings; v.3 is a
final update to agree with the published paper, and also corrects a minor
error that appeared in the published version of the appendi