Table of Contents
Fetching ...

Counting bare curves

Tobias Ekholm, Vivek Shende

Abstract

We construct a class of perturbations of the Cauchy-Riemann equations for maps from curves to a Calabi-Yau threefold. Our perturbations vanish on components of zero symplectic area. For generic 1-parameter families of perturbations, the locus of solution curves without zero-area components is compact, transversely cut out, and satisfies certain natural coherence properties. For curves without boundary, this yields a reduced Gromov-Witten theory in the sense of Zinger. That is, we produce a well defined invariant given by counting only maps without components of zero symplectic area, and we show that this invariant is related to the usual Gromov-Witten invariant by the expected change of variables. For curves with boundary on Maslov zero Lagrangians, our construction provides an `adequate perturbation scheme' with the needed properties to set up the skein-valued curve counting, as axiomatized in our previous work. The main technical content is the construction, over the Hofer-Wysocki-Zehnder Gromov-Witten configuration spaces, of perturbations to which the `ghost bubble censorship' argument can be applied. Certain local aspects of this problem were resolved in our previous work. The key remaining difficulty is to ensure inductive compatibilities, despite the non-existence of marked-point-forgetting maps for the configuration spaces.

Counting bare curves

Abstract

We construct a class of perturbations of the Cauchy-Riemann equations for maps from curves to a Calabi-Yau threefold. Our perturbations vanish on components of zero symplectic area. For generic 1-parameter families of perturbations, the locus of solution curves without zero-area components is compact, transversely cut out, and satisfies certain natural coherence properties. For curves without boundary, this yields a reduced Gromov-Witten theory in the sense of Zinger. That is, we produce a well defined invariant given by counting only maps without components of zero symplectic area, and we show that this invariant is related to the usual Gromov-Witten invariant by the expected change of variables. For curves with boundary on Maslov zero Lagrangians, our construction provides an `adequate perturbation scheme' with the needed properties to set up the skein-valued curve counting, as axiomatized in our previous work. The main technical content is the construction, over the Hofer-Wysocki-Zehnder Gromov-Witten configuration spaces, of perturbations to which the `ghost bubble censorship' argument can be applied. Certain local aspects of this problem were resolved in our previous work. The key remaining difficulty is to ensure inductive compatibilities, despite the non-existence of marked-point-forgetting maps for the configuration spaces.
Paper Structure (43 sections, 43 theorems, 129 equations, 2 figures)

This paper contains 43 sections, 43 theorems, 129 equations, 2 figures.

Key Result

Theorem 1.1

Let $X$ be a Calabi-Yau 3-fold, and $L \subset X$ a (possibly empty) Lagrangian submanifold of Maslov index zero. Fix a class $d \in H_2(X, L)$, and choose some integer $\chi_{\min}$. We write $\mathbf{Z}$ for the HWZ-GW configuration space of maps realizing class $d$ with possibly disconnected doma

Figures (2)

  • Figure 1: Induced perturbations in (1c). Left, smoothing of a rational bubble with two tori attached. Right, the same domain appearing when tori are attached directly. The induced perturbations are different, supports are indicated in grey, but close provided the gluing parameter cut off is supported at large gluing parameter.
  • Figure 2: The different contributions for (2). For $\epsilon_2^\beta$ sufficiently small the perturbation on the domain to the right is cut off and only the perturbation from the domain on the left contributes.

Theorems & Definitions (104)

  • Theorem 1.1
  • Remark 1.2
  • Corollary 1.3
  • Theorem 1.4: \ref{['c : bare to GW']}
  • Remark 1.5
  • Remark 1.6
  • Example 2.1
  • Definition 3.1
  • Remark 3.2
  • Definition 3.3
  • ...and 94 more