Closing the interpolation-algebra generating-rank gap

Close the gap between the linear lower bound and the exponential upper bound on the generating rank of interpolation algebras for $\mathcal T_k$, or construct an interpolation algebra with a substantially smaller generating rank.

Background

For the class Tk\mathcal T_k of tropical polynomials with tropical decomposition width at most kk, the paper establishes a linear lower bound on the generating rank of any interpolation algebra and an upper bound of e(1+o(1))ke^{(1+o(1))k}. The authors note that the cyclic tropical polynomial construction attains the latter bound within that construction, so improving the upper bound polynomially would require a different algebraic construction.

References

Can the gap between the lower and upper bounds on the generating rank of interpolation algebras for $\mathcal T_k$ be closed? We currently have a linear lower bound and an upper bound of $e{(1+o(1))k}$.

On the Structure of $(\min,+)$ Convolution  (2608.13310 - Zhou, 13 Aug 2026) in Section titled “Open Problems”