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arXiv · 2104.11166

Naruse hook formula for linear extensions of mobile posets

GaYee Park
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Abstract

Linear extensions of posets are important objects in enumerative and algebraic combinatorics that are difficult to count in general. Families of posets like Young diagrams of straight shapes and $d$-complete posets have hook-length product formulas to count linear extensions, whereas families like Young diagrams of skew shapes have determinant or positive sum formulas like the Naruse hook-length formula from 2014. In 2020, Garver et. al. gave determinant formulas to count linear extensions of a family of posets called mobile posets that refine $d$-complete posets and border strip skew shapes. We give a Naruse type hook-length formula to count linear extensions of such posets by proving a major index $q$-analogue. We also a inversion index $q$-analogue of the Naruse formula for mobile tree posets.

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GaYee Park. 2021-04-22. Naruse hook formula for linear extensions of mobile posets. https://arxiv.org/abs/2104.11166

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