Séminaire Lotharingien de Combinatoire, B87b (2023), 20 pp.

Aritra Bhattacharya

Haglund's Positivity Conjecture for Multiplicity One Pairs

Abstract. Haglund's conjecture states that ⟨Jλ(q,qk),sμ⟩ / (1-q)|λ|Z≥0[q] for all partitions λ,μ and all non-negative integers k, where Jλ is the integral form Macdonald symmetric function and sμ is the Schur function. This paper proves Haglund's conjecture in the cases when the pair (λ,μ) satisfies Kλ,μ=1 or Kμ',λ'=1 where K denotes the Kostka number. We also obtain some general results about the transition matrix between Macdonald symmetric functions and Schur functions.


Received: July 1, 2022. Revised: January 30, 2023. Accepted: February 5, 2023.

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