# Homomesy in products of three chains and multidimensional recombination

## TL;DR

This paper extends the concept of homomesy to the product of three chains with specific conditions, generalizes the recombination technique to higher dimensions, and explores related combinatorial structures and posets.

## Contribution

It proves a new homomesy result for the product of three chains with one chain of two elements and generalizes recombination to n-dimensional posets.

## Key findings

- Homomesy holds for the product of three chains with one chain of two elements.
- Recombination technique is generalized to n-dimensional posets.
- Partial homomesy results are obtained for larger products of chains.

## Abstract

J. Propp and T. Roby isolated a phenomenon in which a statistic on a set has the same average value over any orbit as its global average, naming it homomesy. They proved that the cardinality statistic on order ideals of the product of two chains poset under rowmotion exhibits homomesy. In this paper, we prove an analogous result in the case of the product of three chains where one chain has two elements. In order to prove this result, we generalize from two to $n$ dimensions the recombination technique that D. Einstein and Propp developed to study homomesy. We see that our main homomesy result does not fully generalize to an arbitrary product of three chains, nor to larger products of chains; however, we have a partial generalization to an arbitrary product of three chains. Additional corollaries include refined homomesy results in the product of three chains and a new result on increasing tableaux. We conclude with a generalization of recombination to any ranked poset and a homomesy result for the Type B minuscule poset cross a two element chain.