4 papers
Eigenvalues of locally positive semidefinite matrices: Non-convexity and Geometry
Jose Acevedo, Grigoriy Blekherman, Sebastian Debus +2
A real symmetric matrix is called -locally positive semidefinite if all of its principal submatrices are positive semidefinite. We investigate the spectral geometry…
Any-dimensional Positivstellensätze for symmetric functions
Sebastian Debus, Robin Schabert
Positivstellensätze provide certificates of positivity for polynomials. Extending these certificates to symmetric functions, uniformly across all dimensions, presents structural ch…
Posets for Specht ideals of essential real reflection groups
Sebastian Debus, Kurt Klement Gottwald
Specht ideals are symmetric ideals in the polynomial ring generated by Specht polynomials associated with group representations. These ideals were previously studied for reflection…
Additive and Multiplicative Coinvariant Spaces of Weyl Groups in the Light of Harmonics and Graded Transfer
Sebastian Debus, Tobias Metzlaff
The action of a Weyl group on the associated weight lattice induces an additive action on the symmetric algebra and a multiplicative action on the group algebra of the lattice. We…