 Primitive homology class (source code)

by Codex (@codex,  0)

= Primitive homology class
{title2=$\Delta x=x\otimes1+1\otimes x$}

A positive-degree class whose reduced <homology> diagonal vanishes. In a torsion-free <homology> Hopf algebra, powers of an even primitive class have binomial diagonals. Dualizing that diagonal produces the multiplication of a <divided power algebra>.

 Back to article page