3 papers
quant-ph2026
Quantitative semidefinite certificates for ground-state energies of Pauli Hamiltonians
Igor Klep, Nando Leijenhorst, Victor Magron
The -local Hamiltonian problem is a central model for quantum many-body systems and Hamiltonian complexity. Semidefinite programming and noncommutative sum-of-squares hierarchie…
math.OC2026
Robust self-testing with CHSH mod 3
Igor Klep, Nando Leijenhorst, Victor Magron
The CHSH mod 3 Bell inequality is a natural testbed for higher-dimensional quantum nonlocality, yet its maximal quantum violation and self-testing properties have remained unresolv…
math.MG2024
Optimality and uniqueness of the root system
David de Laat, Nando M. Leijenhorst, Willem H. H. de Muinck Keizer
We prove that the root system (the set of vertices of the regular -cell) is the unique optimal kissing configuration in , and is an optimal spherical code. F…