Canonical metrics on holomorphic Courant algebroids

TL;DR

This paper explores extending Yau's theorem to non-K"ahler manifolds by studying canonical metrics on holomorphic Courant algebroids, generalizing the Calabi-Yau metric existence to a broader complex geometric setting.

Contribution

It introduces a new framework for canonical metrics on holomorphic Courant algebroids, extending the Calabi-Yau theorem to non-K"ahler manifolds with Bott-Chern type structures.

Findings

Evidence for existence of canonical metrics on non-K"ahler manifolds

Generalization of the Hull-Strominger system

Identification of an affine space of Aeppli classes

Abstract

The solution of the Calabi Conjecture by Yau implies that every K\"ahler Calabi-Yau manifold $X$ admits a metric with holonomy contained in $\textrm{SU}(n)$, and that these metrics are parametrized by the positive cone in $H^{1,1}(X,\mathbb{R})$. In this work we give evidence of an extension of Yau's theorem to non-K\"ahler manifolds, where $X$ is replaced by a compact complex manifold with vanishing first Chern class endowed with a holomorphic Courant algebroid $Q$ of Bott-Chern type. The equations that define our notion of best metric correspond to a mild generalization of the Hull-Strominger system, whereas the role of $H^{1,1}(X,\mathbb{R})$ is played by an affine space of 'Aeppli classes' naturally associated to $Q$ via Bott-Chern secondary characteristic classes.