A recursive method for the oddness of the number of set-valued tableaux
Taikei Fujii, Takahiko Nobukawa, Tatsushi Shimazaki
TL;DR
The paper addresses the parity of $|{ m SVT}( heta,n)|$ for skew diagrams, showing it is always odd. It develops a recursive, constructive induction by removing the bottom-right box and classifying extensions, complemented by a sign-reversing involution to cancel even contributions. The result highlights a robust oddness property for set-valued tableaux and connects to the tableau-sum framework for Grothendieck polynomials, with multiple alternative proofs provided in appendices. These findings enrich the combinatorial understanding underpinning K-theoretic Schubert calculus and offer versatile methodological perspectives for parity arguments in tableau combinatorics.
Abstract
Set-valued tableaux, introduced by Buch to express the tableaux-sum formula for stable Grothendieck polynomials, generalize semistandard tableaux. We provide a new recursive proof that the number of set-valued tableaux of a given shape is odd.
