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math.CO2025
Sparse Paving Positroids
John Machacek, George D. Nasr
Using Postnikov's Le-diagrams, decorated permutations, and Grassmann necklaces, we classify which positroids are sparse paving matroids. This allows us to enumerate sparse paving p…
math.CO2025
Group Actions and Some Combinatorics on Words with
John Machacek
We introduce generalizations of powers and factor complexity via orbits of group actions. These generalizations include concepts like abelian powers and abelian complexity. It is s…