2021 Theses Doctoral

Relative Gromov-Witten Invariants - A Computation

Dolfen, Clara

We will compute relative Gromov--Witten invariants of maximal contact order by applying the virtual localization formula to the moduli space of relative stable maps. In particular, we will enumerate genus 0 stable maps to the Hirzebruch surface 𝔽₁ = ℙ(𝒪_ℙ¹ ⊕ 𝒪_ℙ¹ (1)) relative to the divisor 𝐷 = 𝐵 + 𝐹, where 𝐵 is the base and 𝐹 the fiber of the projective bundle. We will provide an explicit description of the connected components of the fixed locus of the moduli space 𝑀̅₀,𝑛 (𝔽₁ ; 𝐷|𝛽 ; 𝜇) using decorated colored graphs and further determine the weight decomposition of their virtual normal bundles. This thesis contains explicit computations for 𝜇 = (3) and 𝛽 = 3𝐹 + 𝐵), and additionally 𝜇 = (4) and 𝛽 ∈ {4𝐹 + 𝐵, 4𝐹 + 2𝐵}. The same methodology however can be applied to any other ramification pattern 𝜇 and curve class 𝛽.