Homomesies on permutations -- an analysis of maps and statistics in the FindStat database
Combinatorics
2024-06-07 v3
Abstract
In this paper, we perform a systematic study of permutation statistics and bijective maps on permutations in which we identify and prove 122 instances of the homomesy phenomenon. Homomesy occurs when the average value of a statistic is the same on each orbit of a given map. The maps we investigate include the Lehmer code rotation, the reverse, the complement, the Foata bijection, and the Kreweras complement. The statistics studied relate to familiar notions such as inversions, descents, and permutation patterns, and also more obscure constructs. Beside the many new homomesy results, we discuss our research method, in which we used SageMath to search the FindStat combinatorial statistics database to identify potential homomesies.
Keywords
Cite
@article{arxiv.2206.13409,
title = {Homomesies on permutations -- an analysis of maps and statistics in the FindStat database},
author = {Jennifer Elder and Nadia Lafrenière and Erin McNicholas and Jessica Striker and Amanda Welch},
journal= {arXiv preprint arXiv:2206.13409},
year = {2024}
}