4 papers
Ordered set partition posets
Bruce E Sagan, Sheila Sundaram
A set partition is said to be ordered if the blocks of the partition are listed in a specific order. The ordered set partitions of , with a unique minimal element a…
Stability and ribbon bases for the rank-selected homology of geometric lattices
Patricia Hersh, Sheila Sundaram
This paper analyzes the representation theoretic stability, in the sense of Thomas Church and Benson Farb, of the rank-selected homology of the Boolean lattice and the partition la…
Koszulity, supersolvability, and Stirling representations
Ayah Almousa, Victor Reiner, Sheila Sundaram
Supersolvable hyperplane arrangements and matroids are known to give rise to certain Koszul algebras, namely their Orlik-Solomon algebras and graded Varchenko-Gel'fand algebras. We…
The -positivity of the chromatic symmetric function for twinned paths and cycles
Esther Banaian, Kyle Celano, Megan Chang-Lee +7
The operation of twinning a graph at a vertex was introduced by Foley, Hoà ng, and Merkel (2019), who conjectured that twinning preserves -positivity of the chromatic symmetric…