# Marston Morse Lectures

**Topic: **Exceptional holonomy and related geometric structures: Examples and moduli theory

**Speaker: **Simon Donaldson

**Affiliation: **Stonybrook University

**Date & Time: **Wednesday April 4th, 2018, 2:00pm - 3:00pm

**Location: **Simonyi Hall 101

**Video:** https://video.ias.edu/MarstonMorse/2018/0404-SimonDonaldson

We will discuss the constructions of compact manifolds with exceptional holonomy (in fact, holonomy $G_{2}$), due to Joyce and Kovalev. These both use “gluing constructions”. The first involves de-singularising quotient spaces and the second constructs a 7-manifold from “building blocks” derived from Fano threefolds. We will explain how the local moduli theory is determined by a period map and discuss connections between the global moduli problem and Riemannian convergence theory (for manifolds with bounded Ricci curvature).