We study invariant differential operators on representations of supergroups associated with simple Jordan superalgebras, in the classical case this problem goes back to Kostant. Eigenvalues of Capelli differential operators give interesting families of polynomials such as super Jack polynomials of Sergeev and Veselov and factorial Schur polynomials of Okounkov and Ivanov. We also discuss connection with deformed Calogero-Moser systems in the super case.[-]

Given a representation of a reductive group, Braverman-Finkelberg-Nakajima have defined a remarkable Poisson variety called the Coulomb branch. Their construction of this space was motivated by considerations from supersymmetric gauge theories and symplectic duality. The coordinate ring of this Coulomb branch is defined as a kind of cohomological Hall algebra; thus it makes sense to develop a type of “Springer theory” to define modules over this algebra. In this talk, we will explain this BFN Springer theory and give many examples. In the toric case, we will see a beautiful combinatorics of polytopes. In the quiver case, we will see connections to the representations of quivers over power series rings. In the general case, we will explore the relations between this Springer theory and quasimap spaces.[-]

The so-called BPS states in a conformal field theory with extended supersymmetry are key when assigning a geometric interpretation to the theory. Standard invariants for such theories arise from a net count of BPS, half or quarter BPS states, according to the Z2 grading into ‘bosons' and ‘fermions'. This allows for boson-fermion pairs of states to cease being BPS under deformation of the theory. The talk will give a review of this phenomenon, arguing that it is ubiquitous in theories with geometric interpretation by a K3 surface. For a particular type of deformations, we propose that the process is channelled by the action of SU(2) on an appropriate subspace of the space of states.
This is joint work with Anne Taormina.[-]