English

Bounded affine permutations II. Avoidance of decreasing patterns

Combinatorics 2022-01-13 v1

Abstract

We continue our study of a new boundedness condition for affine permutations, motivated by the fruitful concept of periodic boundary conditions in statistical physics. We focus on bounded affine permutations of size NN that avoid the monotone decreasing pattern of fixed size mm. We prove that the number of such permutations is asymptotically equal to (m1)2NN(m2)/2(m-1)^{2N} N^{(m-2)/2} times an explicit constant as NN\to\infty. For instance, the number of bounded affine permutations of size NN that avoid 321321 is asymptotically equal to 4N(N/4π)1/24^N (N/4\pi)^{1/2}. We also prove a permuton-like result for the scaling limit of random permutations from this class, showing that the plot of a typical bounded affine permutation avoiding m1m\cdots1 looks like m1m-1 random lines of slope 11 whose yy intercepts sum to 00.

Keywords

Cite

@article{arxiv.2008.06406,
  title  = {Bounded affine permutations II. Avoidance of decreasing patterns},
  author = {Neal Madras and Justin M. Troyka},
  journal= {arXiv preprint arXiv:2008.06406},
  year   = {2022}
}
R2 v1 2026-06-23T17:51:47.849Z