arXiv subjects
Publications and source records attributed to Russell Avdek.
We prove that Bourgeois' contact structures on $M \times \mathbb{T}^{2}$ determined by the supporting open books of a contact manifold $(M, \xi)$ are always tight. The proof is based on a contact homology computation leveraging holomorphic foliations and Kuranishi structures.
We describe symplectic mapping class relations between products of positive Dehn twists along Lagrangian spheres in Weinstein $4$-manifolds, all of which are affine $\mathbb{C}$ varieties. The relations are obtained by applying classification results for Fano $3$-folds and polarized $K3$ surfaces of small genus to a general methodology -- finding pencil pairs.
A stabilization operation is defined for codimension $2$ contact submanifolds in $\dim \geq 5$ contact manifolds $(M, \xi)$. The definition is such that (1) a given $(M, \xi)$ is overtwisted iff its standard transverse unknot is stabilized and (2) transverse stabilization preserves the formal contact isotopy class and intrinsic contact structure of a link. We prove that many transverse links are non-simple.
Let $\xi$ be a $\tau$-invariant contact structure on $N(W) = \mathbb{R}_{\tau} \times W$ for a closed, $2n$-dimensional manifold $W$, so that each $\{\tau\} \times W$ is a convex hypersurface. When $n=1$, Giroux's criterion provides a simple means of determining exactly when $\xi$ is tight. It is an open problem to find a generalization applicable for $n>1$. This article solves an algebraic version of the problem, determining exactly when $(N(W), \xi)$ has non-vanishing contact homology ($CH$) and computing $CH(N(W), \xi)$ when it is non-zero. The result can be expressed in terms of homotopy equivalence of augmentations of the chain level $CH$ algebra of the dividing set or in terms of bilinearized homology theories, which we define for free, commutative DGAs over $\mathbb{Q}$. Our proof relies on the development of obstruction bundle gluing in the Kuranishi setting.
We define a new algebra associated to a Legendrian submanifold $\Lambda$ of a contact manifold of the form $\mathbb{R}_{t} \times W$, called the planar diagram algebra and denoted $PDA(\Lambda, \mathcal{P})$. It is a non-commutative, filtered, differential graded algebra whose filtered stable tame isomorphism class is an invariant of $\Lambda$ together with a partition $\mathcal{P}$ of its connected components. When $\Lambda$ is connected, $PDA$ is the Chekanov-Eliashberg algebra. In general, the $PDA$ differential counts holomorphic disks with multiple positive punctures using a combinatorial framework inspired by string topology.
We study moduli spaces $\mathcal{M}$ of holomorphic maps $U$ from Riemann surfaces to $\mathbb{R}^{4}$ with boundaries on the Lagrangian cylinder over a Legendrian link $\Lambda \subset (\mathbb{R}^{3}, \xi_{std})$. We allow our domains, $\Sigma$, to have non-trivial topology in which case $\mathcal{M}$ is the zero locus of an obstruction function $\mathcal{O}$, sending a moduli space of holomorphic maps in $\mathbb{C}$ to $H^{1}(\Sigma)$. In general, $\mathcal{O}^{-1}(0)$ is not combinatorially computable. However after a Legendrian isotopy, $\Lambda$ can be made left-right-simple, implying that any $U$ of index $1$ is a disk with one or two positive punctures for which $\pi_{\mathbb{C}}\circ U$ is an embedding. Moreover, any $U$ of index $2$ is either a disk or an annulus with $\pi_{\mathbb{C}} \circ U$ simply covered and without interior critical points. Therefore any SFT invariant of $\Lambda$ is combinatorially computable using only disks with $\leq 2$ positive punctures.
Let $\Lambda^{\pm} = \Lambda^{+} \cup \Lambda^{-} \subset (\mathbb{R}^{3}, \xi_{std})$ be a contact surgery diagram determining a closed, connected contact $3$-manifold $(S^{3}_{\Lambda^{\pm}}, \xi_{\Lambda^{\pm}})$ and an open contact manifold $(\mathbb{R}^{3}_{\Lambda^{\pm}}, \xi_{\Lambda^{\pm}})$. Following arXiv:0911.0026 and arXiv:1906.07228 we demonstrate how $\Lambda^{\pm}$ determines a family $\alpha_{\epsilon}$ of contact forms on $(\mathbb{R}^{3}_{\Lambda^{\pm}}, \xi_{\Lambda^{\pm}})$ whose closed Reeb orbits are in one-to-one correspondence with cyclic words of composable Reeb chords on $\Lambda^{\pm}$. We compute the homology classes and integral Conley-Zehnder indices of these orbits diagrammatically and develop algebraic tools for studying holomorphic curves in surgery cobordisms between the $(\mathbb{R}^{3}_{\Lambda^{\pm}}, \xi_{\Lambda^{\pm}})$. These new techniques are used to describe the first known examples of closed, tight contact manifolds with vanishing contact homology. They are contact $\frac{1}{k}$ surgeries along the right-handed, $tb=1$ trefoil for $k > 0$, which are known to have non-zero Heegaard-Floer contact classes by arXiv:math/0404135.
In this paper, we examine mapping class group relations of some symplectic manifolds. For each $n\geq 1$ and $k \geq 1$, we show that the $2n$-dimensional Weinstein domain $W = \{f=\delta\} \cap B^{2n+2}$, determined by the degree $k$ homogeneous polynomial $f\in \mathbb{C}[z_0,\dots,z_n]$, has a Boothby-Wang type boundary and a right-handed fibered Dehn twist along the boundary that is symplectically isotopic to a product of right-handed Dehn twists along Lagrangian spheres. We also present explicit descriptions of the symplectomorphisms in the case $n=2$ recovering the classical chain relation for the torus with two boundary components.
The purpose of this paper is to introduce Liouville hypersurfaces in contact manifolds, which generalize ribbons of Legendrian graphs and pages of supporting open books. Liouville hypersurfaces are used to define a gluing operation for contact manifolds called the Liouville connect sum. Performing this operation on a contact manifold $(M, \xi)$ gives an exact -- and in many cases, Weinstein -- cobordism whose concave boundary is $(M, \xi)$ and whose convex boundary is the surgered manifold. These cobordisms are used to establish the existence of "fillability" and "non-vanishing contact homology" monoids in symplectomorphism groups of Liouville domains, study the symplectic fillability of a family of contact manifolds which fiber over the circle, associate cobordisms to certain branched coverings of contact manifolds, and construct exact symplectic cobordisms that do not admit Weinstein structures. The Liouville connect sum generalizes the Weinstein handle attachment and is used to extend the definition of contact $(1/k)$-surgery along Legendrian knots in contact 3-manifolds to contact $(1/k)$-surgery along Legendrian spheres in contact manifolds of arbitrary dimension. We use contact surgery to construct exotic contact structures on $5$- and $13$-dimensional spheres after establishing that $S^{2}$ and $S^{6}$ are the only spheres along which generalized Dehn twists smoothly square to the identity mapping. The exoticity of these contact structures implies that Dehn twists along $S^{2}$ and $S^{6}$ do not symplectically square to the identity, generalizing a theorem of Seidel. A similar argument shows that the $(2n+1)$-dimensional contact manifold determined by an open book whose page is $(T^{*}S^{n}, -\lambda_{can})$ and whose monodromy is any negative power of a symplectic Dehn twist is not exactly fillable.
Let $(M,\xi)$ be a contact 3-manifold. We present two new algorithms, the first of which converts an open book $(\Sigma,\Phi)$ supporting $(M,\xi)$ with connected binding into a contact surgery diagram. The second turns a contact surgery diagram for $(M,\xi)$ into a supporting open book decomposition. These constructions lead to a refinement of a result of Ding-Geiges, which states that every such $(M,\xi)$ may be obtained by contact surgery from $(S^{3},\xi_{std})$, as well as bounds on the support norm and genus of contact manifolds obtained by surgery in terms of classical link data. We then introduce Kirby moves called ribbon moves which use mapping class relations to modify contact surgery diagrams. Any two surgery diagrams of the same contact 3-manifold are related by a sequence of Legendrian isotopies and ribbon moves. As most of our results are computational in nature, a number of examples are analyzed.