Maths HEP Lunchtime Seminars: Bethe Ansatz for Yangian Invariants: Towards Scattering Amplitudes
1 November 2013 13:00 in CM221
Inspired by Baxter's perimeter Bethe ansatz we present a method to construct Yangian invariants. The condition for Yangian invariance is formulated as an eigenvalue problem of certain monodromies that can be solved using Bethe ansatz techniques. The rather general principle is being worked out for rational inhomogeneous spin chains with finite-dimensional representations of gl(n) in the quantum space. Using the algebraic Bethe ansatz we derive Bethe ansatz equations for Yangian invariants and study the corresponding on-shell Bethe vectors. Furthermore, we show how they can be reformulated in terms of contour integrals. This aspect is reminiscent of an on-shell formulation of scattering amplitudes in N=4 super Yang-Mills theory.