activity
19982026
most citedEquivalence Classes of Permutations under Various Relations Generated by Constrained Transpositions

11 citations · 33 across the 13 of their papers we have counts for

collaborators

17 papers

math.CO2026

Detropicalization as a proof technique

Darij Grinberg, Tom Roby

Rational functions make sense over any commutative ring, as long as the denominators are invertible. When there is no subtraction involved, they even apply over semirings (rings wi…

math.CO2024

Monomial identities in the Weyl algebra

Darij Grinberg, Tom Roby, Stephan Wagner +1

Motivated by a question and some enumerative conjectures of Richard Stanley, we explore the equivalence classes of words in the Weyl algebra, $\mathbf{k} \left< D,U \mid DU - UD =…

math.CO2024

Rowmotion on the chain of V's poset and whirling dynamics

Matthew Plante, Tom Roby

Given a finite poset , we study the _whirling_ action on vertex-labelings of with the elements . When such labelings are (weakly) order-reversing, we ca…

math.CO2022

Birational rowmotion on a rectangle over a noncommutative ring

Darij Grinberg, Tom Roby

We extend the periodicity of birational rowmotion for rectangular posets to the case when the base field is replaced by a noncommutative ring (under appropriate conditions). This r…

math.CO2021

Rowmotion on fences

Sergi Elizalde, Matthew Plante, Tom Roby +1

A fence is a poset with elements F = {x_1, x_2, ..., x_n} and covers x_1 < x_2 < ... < x_a > x_{a+1} > ... > x_b < x_{b+1} < ... where a, b, ... are positive integers. We investiga…

math.CO2020★ 2 cited

Foatic actions of the symmetric group and fixed-point homomesy

Michael LaCroix, Tom Roby

We study maps on the set of permutations of n generated by the Rényi-Foata map intertwined with other dihedral symmetries (of a permutation considered as a 0-1 matrix). Iterating t…