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Dan Pomerleano

Publications and source records attributed to Dan Pomerleano.

3 recordsLinked to original sources

The quantum connection and its mod p reduction

Recent progress on the structure of the quantum connection for monotone symplectic manifolds has used two approaches, which share the common feature of reducing to mod $p$ coefficients. We refine and compare those approaches. In particular, we establish a relation with quantum Steenrod operations which is stronger than that in Chen's work, leading to more precise information about the singularity at $\infty$ of the quantum connection. For the version of the connection relative to a smooth anticanonical divisor, we draw attention to the implications of the categorical mod $p$ Fontaine-Laffaille structure established by Petrov-Vaintrob-Vologodsky.

math.SG

Affine nil-Hecke algebras and Quantum cohomology

Let $G$ be a compact, connected Lie group and $T \subset G$ a maximal torus. Let $(M,ω)$ be a monotone closed symplectic manifold equipped with a Hamiltonian action of $G$. We construct a module action of the affine nil-Hecke algebra $\hat{H}_*^{S^1 \times T}(LG/T)$ on the $S^1 \times T$-equivariant quantum cohomology of $M$, $QH^*_{S^1 \times T}(M).$ Our construction generalizes the theory of shift operators for Hamiltonian torus actions [OP,LJ]. We show that, as in the abelian case, this action behaves well with respect to the quantum connection. As an application of our construction, we show that when $G$ is semi-simple, the $G$-equivariant quantum cohomology $QH_G^*(M)$ defines a canonical holomorphic Lagrangian subvariety $\mathbb{L}_G(M) \hookrightarrow BFM(G_{\mathbb{C}}^{\vee})$ in the BFM-space of the Langlands dual group, confirming an expectation of Teleman from [T1].

math.SG

Torsion contact forms in three dimensions have two or infinitely many Reeb orbits

We prove that every nondegenerate contact form on a closed connected three-manifold, such that the associated contact structure has torsion first Chern class, has either two or infinitely many simple Reeb orbits. By previous results it follows that under the above assumptions, there are infinitely many simple Reeb orbits if the three-manifold is not the three-sphere or a lens space. We also show that for non-torsion contact structures, every nondegenerate contact form has at least four simple Reeb orbits.

math.SG