Points on rational normal curves and the ABCT variety

Authors

  • D. Agostini University of Tübingen, Germany
  • L. Ramesh University of Bielefeld, Germany
  • D. Shen University of Michigan, United States

Keywords:

rational normal curve, configurations, Grassmannian, positive geometry, spinor helicity, scattering equations

Abstract

The ABCT variety is defined as the closure of the image of G(2, n) under the Veronese map. We realize the ABCT variety V(3,n) as the determinantal variety of a vector bundle morphism. We use this to give a recursive formula for the fundamental class of V(3,n). As an application, we show that special Schubert coefficients of this class are given by Eulerian numbers, matching a formula by Cachazo-He-Yuan. On the way tothis, we prove that the variety of configuration of points on a common divisor on a smooth variety is reduced and irreducible, generalizing a result of Caminata-Moon-Schaffler.

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Published

2025-05-23

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Section

Articoli