Published online by Cambridge University Press: 01 August 2018
Athanasiadis [‘A survey of subdivisions and local $h$-vectors’, in The Mathematical Legacy of Richard P. Stanley (American Mathematical Society, Providence, RI, 2017), 39–51] asked whether the local $h$-polynomials of type $A$ cluster subdivisions have only real zeros. We confirm this conjecture and prove that the local $h$-polynomials for all the Cartan–Killing types have only real roots. Our proofs use multiplier sequences and Chebyshev polynomials of the second kind.
This work was supported by the National Science Foundation of China (Nos. 11626172 and 11701424), the TJNU Funding for Scholars Studying Abroad, the PhD Program of TJNU (No. XB1616) and MECF of Tianjin (No. JW1713).