Almost-K\"ahler smoothings of compact complex surfaces with $A_1$ singularities

TL;DR

This paper demonstrates the existence of constant Hermitian scalar curvature metrics on almost-K"ahler smoothings of certain singular K"ahler orbifolds, extending geometric structures through smoothing processes.

Contribution

It introduces a method to construct almost-K"ahler structures with constant Hermitian curvature on smoothings of orbifolds with $A_1$ singularities, without nontrivial holomorphic vector fields.

Findings

Existence of constant Hermitian scalar curvature metrics on smoothings

Construction of almost-K"ahler structures on smoothed manifolds

Identification of vanishing cycles as Hamiltonian stationary surfaces

Abstract

This paper is concerned with the existence of metrics of constant Hermitian scalar curvature on almost-K\"ahler manifolds obtained as smoothings of a constant scalar curvature K\"ahler orbifold, with $A_1$ singularities. More precisely, given such an orbifold that does not admit nontrivial holomorphic vector fields, we show that an almost-K\"ahler smoothing $(M_\varepsilon, \omega_\varepsilon)$ admits an almost-K\"ahler structure $(\hat J_\varepsilon, \hat g_\varepsilon)$ of constant Hermitian curvature. Moreover, we show that for $\varepsilon>0$ small enough, the $(M_\varepsilon, \omega_\varepsilon)$ are all symplectically equivalent to a fixed symplectic manifold $(\hat M, \hat \omega)$ in which there is a surface $S$ homologous to a 2-sphere, such that $[S]$ is a vanishing cycle that admits a representant that is Hamiltonian stationary for $\hat g_\varepsilon$.