On $\mathbb{A}$-generators of the cohomology $H^{*}(V^{\oplus 5})=\mathbb{Z}/2[u_1,\ldots,u_5]$ and the cohomological transfer of rank 5

Fuente: arXiv
Saved in:
Bibliographic Details
Main Author: Phuc, Dang Vo
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866915693916585984
author Phuc, Dang Vo
author_facet Phuc, Dang Vo
contents Computing the cohomology of the 2-primary Steenrod algebra $\mathbb{A}$ is a central problem in algebraic topology, as it forms the $E_2$-term of the Adams spectral sequence converging to the stable homotopy groups of spheres. The Singer cohomological transfer, $φ_n$, is a key homomorphism for characterizing this cohomology. Singer conjectured that $φ_n$ is always a monomorphism. The Singer transfer is closely linked to the Peterson hit problem, which seeks a minimal generating set for the $\mathbb{A}$-module $H^{*}(V^{\oplus n}) = \mathbb{Z}/2[u_1, \ldots, u_n]$, also unsolved for $n \geq 5$. In this paper, we study the hit problem for $H^{*}(V^{\oplus 5})$ and verify Singer's conjecture for the case $n=5$ in the general degree $d = 2^{t+5} + 2^{t+2} + 2^{t+1}-5$ for any non-negative integer $t$. We demonstrate that the Singer cohomological transfer is an isomorphism for $n=5$ in degree $d$. This provides a positive answer to Singer's conjecture in these specific cases. The appendix provides our new algorithm implemented on the computer algebra system OSCAR, through which all principal results of this paper have been completely verified.
format Preprint
id arxiv_https___arxiv_org_abs_2511_11745
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle On $\mathbb{A}$-generators of the cohomology $H^{*}(V^{\oplus 5})=\mathbb{Z}/2[u_1,\ldots,u_5]$ and the cohomological transfer of rank 5
Phuc, Dang Vo
Algebraic Topology
55T15, 55S10, 55S05, 55R12
Computing the cohomology of the 2-primary Steenrod algebra $\mathbb{A}$ is a central problem in algebraic topology, as it forms the $E_2$-term of the Adams spectral sequence converging to the stable homotopy groups of spheres. The Singer cohomological transfer, $φ_n$, is a key homomorphism for characterizing this cohomology. Singer conjectured that $φ_n$ is always a monomorphism. The Singer transfer is closely linked to the Peterson hit problem, which seeks a minimal generating set for the $\mathbb{A}$-module $H^{*}(V^{\oplus n}) = \mathbb{Z}/2[u_1, \ldots, u_n]$, also unsolved for $n \geq 5$. In this paper, we study the hit problem for $H^{*}(V^{\oplus 5})$ and verify Singer's conjecture for the case $n=5$ in the general degree $d = 2^{t+5} + 2^{t+2} + 2^{t+1}-5$ for any non-negative integer $t$. We demonstrate that the Singer cohomological transfer is an isomorphism for $n=5$ in degree $d$. This provides a positive answer to Singer's conjecture in these specific cases. The appendix provides our new algorithm implemented on the computer algebra system OSCAR, through which all principal results of this paper have been completely verified.
title On $\mathbb{A}$-generators of the cohomology $H^{*}(V^{\oplus 5})=\mathbb{Z}/2[u_1,\ldots,u_5]$ and the cohomological transfer of rank 5
topic Algebraic Topology
55T15, 55S10, 55S05, 55R12
url https://arxiv.org/abs/2511.11745