Sebastian Schlegel Mejia

I am a PhD student at the University of Edinburgh. My advisor is Ben Davison.

Email: s (dot) schlegel-mejia (at) sms (dot) ed (dot) ac (dot) uk

Research interests

My general interests lie in moduli spaces and enumerative geometry. More specifically, I have been interested in categorified Donaldson–Thomas theory, cohomology and derived categories of moduli spaces, and cohomological/categorical Hall algebras


BPS cohomology for rank 2 degree 0 Higgs bundles (and more) (submitted)


Together with Ben Davison and Lucien Hennecart I am organising the EGRET seminar.

Together with Ben Brown, I organized the Hodge Club for the academic year 2020-2021.

Current Teaching

General Topology (Tutor), Geometry (Tutor) at the University of Edinburgh



December 2022, Glasgow, "Workshop on Singularities and Mirror Symmetry"


October 2022, Aussois, Workshop "Donaldson--Thomas invariants in Aussois"
September 2022, London, "5th BrAG meeting"
August 2022, Cetraro, School on "Hyperkähler manifolds and related geometries"
June-July 2022, Lisbon, "School on Mirror Symmetry and Moduli Spaces"
June 2022, Levico Terme, Conference "New Perspectives on Hyperkähler Manifolds"
June 2022, Levico Terme, School on "Moduli spaces and stability conditions"
May 2022, Paris, Conference "GAeL XXIX"
October 2021, Oberwolfach, Oberwolfach Seminar: "New Techniques in Resolutions of Singularities"
July 2021, Paris, IHÉS Summer school: "Enumerative Geometry, Physics and Representation Theory"
February 2020, Bonn, Hausdorff School: “Perverse Sheaves in Enumerative Geometry”,