New Combinatorial Formulae for Nested Bethe Vectors

We give new combinatorial formulae for vector-valued weight functions (off-shell nested Bethe vectors) for the evaluation modules over the Yangian $Y(\mathfrak{gl}_4)$.

The case of $Y(\mathfrak{gl}_n)$ for an arbitrary $n$ is considered in [Lett.

Math.

Phys.

115 (2025), 12, 20 pages, arXiv:2402.15717].