Rigorous inhomogeneous spin Whittaker scaling and orthogonality

Prove rigorously that the inhomogeneous spin q-Whittaker polynomials converge under the specified q\to1 scaling to the inhomogeneous spin Whittaker functions, and establish the corresponding continuous orthogonality identity with the Sklyanin-type density, including the required convergence and decay estimates.

Background

The paper formally introduces inhomogeneous spin Whittaker functions as q\to1 scaling limits of the spin q-Whittaker polynomials. The proposed scaling sends x_i=q{X_i}, a_i=q{A_i}, b_i=q{B_i}, and indexes partitions through \lambda_i=\lfloor\log_q(1/L_i)\rfloor.

The resulting continuous orthogonality relation is stated with a Sklyanin-type density and a delta distribution in the Weyl-chamber variables. The discussion is explicitly non-rigorous because proving the limit requires control of q-Pochhammer asymptotics, weak convergence, and decay of the integrands. Thus both the scaling-limit assertion and the continuous orthogonality formula remain conjectural in the inhomogeneous setting.

References

For this reason, to avoid potentially lengthy proofs, we will keep the discussion formal and one can treat the statements presented as conjectures.

Orthogonality of spin $q$-Whittaker polynomials  (2502.00478 - Mucciconi, 1 Feb 2025) in Section 5, subsection “Formal reduction to inhomogeneous spin Whittaker functions”