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Kinematic Stratifications

Algebra & Discrete Mathematics

Speaker: Bernd Sturmfels, MPI Leipzig
Location: 1147 MSB
Start time: Tue, May 13 2025, 2:10PM

We study stratifications of regions in the space of symmetric matrices. Their points are Mandelstam matrices for momentum vectors in particle physics. Kinematic strata in these regions are indexed by signs and rank two matroids. Matroid strata of Lorentzian quadratic forms arise when all signs are non-negative. We characterize the posets of strata, for massless and massive particles, with and without momentum conservation.