Cauchy identities for staircase matrices

Evgeny Feigin, Anton Khoroshkin, Ievgen Makedonskyi

The well known Cauchy identity expresses the product of terms $(1-x_i{y}_j{)}^{-1}$ for $(i,j)$ indexing entries of a rectangular $m\times n$-matrix as a sum over partitions $\lambda$ of…