01 / Hall algebras
Cohomological Hall algebras
Algebraic structures built from moduli stacks, their filtrations and cohomological integrality theorems.
Geometric representation theory · CNRS
Lucien
Hennecart.
I am a CNRS researcher (chargé de recherche) at LAMFA, Université de Picardie Jules Verne, in Amiens, France.
My work lies at the intersection of algebraic geometry and representation theory, with an emphasis on cohomological Hall algebras, BPS Lie algebras, moduli spaces and Calabi–Yau categories.
Research interests
Connecting geometry and algebra
02 / BPS invariants
BPS Lie algebras
BPS cohomology, generalized Kac–Moody structures and representations arising from 2-Calabi–Yau categories.
03 / Moduli geometry
Nonabelian Hodge theory
Moduli stacks of Higgs bundles and local systems, cohomology and comparisons across nonabelian Hodge theory.
04 / Quiver representations
Quivers and counting
Quiver varieties, perverse sheaves, Kac polynomials and geometric constructions in representation theory.
Selected research
Recent papers
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Mackey filtrations for parabolic induction and restriction on smooth stacks, with an application to semistable principal bundles on curves.
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Commutativity of fully nilpotent and seminilpotent CoHAs of the affine plane.
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Hecke operators, BPS cohomology and χ-independence on symplectic surfaces.
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Filtrations and degenerations of CoHAs in terms of current BPS Lie algebras.
Research project · 2027–2031
ReSCoS — ANR JCJC
I am the principal investigator of the ANR JCJC research project ReSCoS, running from January 2027 to December 2031. The project supports research in geometric representation theory and opportunities for doctoral and postdoctoral researchers.
Teaching · Spring 2027
Perverse sheaves
Advanced M2 course for master's and doctoral students, 1 March – 9 April 2027, as part of the Paris M2 Mathématiques Fondamentales programme.
Community
Co-organiser of the GAT seminar in Amiens and meetings in geometric representation theory.
Talks and events →Get in touch
Contact
Office C102 bis · LAMFA, Université de Picardie Jules Verne
33 rue Saint-Leu, 80000 Amiens, France