On a construction for the generators of the polynomial algebra as a module over the Steenrod algebra

Abstract

Let $P_n$ be the graded polynomial algebra ${\mathbb{F}}_2[x_1,x_2,\dots ,x_n]$ with the degree of each generator $x_i$ being 1, where ${\mathbb{F}}_2$ denote the prime field of two elements. The Peterson hit problem is to find a minimal generating set for $P_n$ regarded as a module over the mod-2 Steenrod algebra, $\mathcal{A}$. Equivalently, we want to find a vector space basis for ${\mathbb{F}}_2{\otimes }_{\mathcal{A}}{P}_n$ in each degree $d$. Such a basis may be represented by a list of monomials of degree $d$. In this paper, we present a construction for the $\mathcal{A}$-generators of $P_n$ and prove some properties of it. We also explicitly determine a basis of ${\mathbb{F}}_2{\otimes }_{\mathcal{A}}{P}_n$ for $n=5$ and the degree $d=15.2^s-5$ with $s$ an arbitrary positive integer. These results are used to verify Singer's conjecture for the fifth Singer algebraic transfer in respective degree.

30 pages. arXiv admin note: text overlap with arXiv:1609.03006; substantial text overlap with arXiv:1609.02250 by other authors