English

Comparing Diagonals on the Associahedra

Algebraic Topology 2024-02-26 v4 Combinatorics

Abstract

We prove that the formula for the diagonal approximation ΔK\Delta_{K} on J. Stasheff's nn-dimensional associahedron Kn+2K_{n+2} derived by the current authors in 2004 agrees with the "magical formula" for the diagonal approximation ΔK\Delta_{K}^{\prime} derived by Markl and Shnider in 2006, by Loday in 2011, and by Masuda, Thomas, Tonks, and Vallette in 2021.

Cite

@article{arxiv.2207.08543,
  title  = {Comparing Diagonals on the Associahedra},
  author = {Samson Saneblidze and Ronald Umble},
  journal= {arXiv preprint arXiv:2207.08543},
  year   = {2024}
}

Comments

The initial posting defines the S-U diagonal $\Delta_K$ on the top dimensional cell of $K_n$; its value on proper faces is given by comultiplicative extension. Version 2 defines $\Delta_K$ on all faces of $K_n$ explicitly. Version 3 incorporates recommendations by the referee. Version 4 cites a paper by Loday. 8 pages, 3 Figures

R2 v1 2026-06-25T01:00:23.315Z