English

On a cyclic inequality with exponents and permutations, and its Shapiro-type analogue

Combinatorics 2021-09-07 v2

Abstract

We prove that the cyclic inequality i=1i=n(xixi+1)ki=1i=nxixσ(i)\sum\limits_{i=1}^{i=n}\left(\frac{x_i}{x_{i+1}}\right)^k\geq\sum\limits_{i=1}^{i=n}\frac{x_i}{x_{\sigma(i)}} holds for kk in a specific range dependant on the permutation σ\sigma. We also show that the same is not true for the Sahpiro-type generalizations.

Keywords

Cite

@article{arxiv.2004.08882,
  title  = {On a cyclic inequality with exponents and permutations, and its Shapiro-type analogue},
  author = {Andrzej Czarnecki and Gabriel Kiciński},
  journal= {arXiv preprint arXiv:2004.08882},
  year   = {2021}
}
R2 v1 2026-06-23T14:56:59.412Z