3 papers
math.CO2025
Extending the ab-index
Elena Hoster, Christian Stump, Lorenzo Vecchi
We prove for finite, graded, bounded posets, that the Poincaré-extended ab-index is obtained from the ab-index via the omega-transformation. This proves a conjecture by Dorpalen-Ba…
math.CO2025
Chow polynomials of simplicial posets with positive -vector are real-rooted
Elena Hoster, Christian Stump
We prove that a finite graded simplicial poset with a top element added has real-rooted Chow and augmented Chow polynomials whenever it has a positive -vector. This class of pos…
math.CO2025
Positive -divisible non-crossing partitions and their Kreweras maps
Christian Krattenthaler, Christian Stump
We study positive -divisible non-crossing partitions and their positive Kreweras maps. In classical types, we describe their combinatorial realisations as certain non-crossing s…