A system of unstable higher Toda brackets

Higher order Toda brackets

We describe two ways to define higher order Toda brackets in a pointed simplicial model category $\mathcal{D}$: one is a recursive definition using model categorical constructions, and the second uses the associated simplicial enrichment. We show that these two definitions agree, by providing a third, diagrammatic, description of the Toda bracket, and explain how it serves as the obstruction to rectifying a certain homotopy-commutative diagram in $\mathcal{D}$.

Toda brackets and cup-one squares for ring spectra

In this paper we prove the laws of Toda brackets on the homotopy groups of a connective ring spectrum and the laws of the cup-one square in the homotopy groups of a commutative connective ring spectrum.

不稳定的高阶 Toda 括号 III

Unstable higher Toda brackets III

本文在带基点空间范畴中归纳构造了 n>2 的不稳定 n 重 Toda 括号，并进一步定义了相应的稳定 Toda 括号。

关于矩形Toda括号与Oda扩张问题

On rectangular Toda brackets and Oda's extension problems

本文引入矩形Toda括号工具，解决了Oda关于在2处局部化的三个球面同伦群的扩张问题，这些难题四十多年来未被攻克。

Motivic Toda 括号

Motivic Toda brackets

本文在不稳定motivic同伦论中构造Toda brackets，证明其基本性质，并给出若干具体例子。

Higher Toda brackets and Massey products

We provide a uniform definition of higher order Toda brackets in a general setting, covering the known cases of long Toda brackets for topological spaces and chain complexes and Massey products for differential graded algebras, among others.

May-Lawrence 矩阵 Toda 括号与第二 James-Hopf 不变量的一种不稳定方法

An Unstable Approach to the May-Lawrence Matrix Toda bracket and the \textit{2}nd James-Hopf Invariant

本文提出 May-Lawrence 矩阵 Toda 括号的不稳定方法，推广相关同伦群同构并建立广义 $H$-公式，从而给出 2 局部化元素 $\ct'\inπ_{26}(S^6)$ 的新构造。

乘性谱序列的Toda括号收敛定理

A Toda bracket convergence theorem for multiplicative spectral sequences

该研究在对称幺模稳定拓扑模型范畴中推广了联系Massey乘积与Toda括号的Moss定理，使其适用于幺模相容滤过导出的乘性谱序列，可应用于motivic相关谱序列的计算。

Determination of the order of the P-image by Toda brackets

The present paper gives a proof of the author's paper in the Proceeding of the International Conference on Homotopy Theory and Related Topics at Korea University (2005), 109--113, on the orders of Whitehead products of iota_n with alpha in pi^n_{n+k}, (n > k+1, k < 25) and improves and extends it. The method is to use composition methods in the homotopy groups of spheres and rotation groups.

n-角范畴中的Toda括号

Toda brackets in n-angulated categories

本文为n-角范畴引入Toda括号，证明其定义一致性、杂耍公式及Heller定理的推广，并给出计算实例及与三角化情形的关系。

Higher Toda brackets and the Adams spectral sequence in triangulated categories

The Adams spectral sequence is available in any triangulated category equipped with a projective or injective class. Higher Toda brackets can also be defined in a triangulated category, as observed by B. Shipley based on J. Cohen's approach for spectra. We provide a family of definitions of higher Toda brackets, show that they are equivalent to Shipley's, and show that they are self-dual. Our main result is that the Adams differential $d_r$ in any Adams spectral sequence can be expressed as an $(r+1)$-fold Toda bracket and as an $r^{\text{th}}$ order cohomology operation. We also show how the …

Universal Toda brackets of ring spectra

We construct and examine the universal Toda bracket of a highly structured ring spectrum R. This invariant of R is a cohomology class in the Mac Lane cohomology of the graded ring of homotopy groups of R which carries information about R and the category of R-module spectra. It determines for example all triple Toda brackets of R and the first obstruction to realizing a module over the homotopy groups of R by an R-module spectrum. For periodic ring spectra, we study the corresponding theory of higher universal Toda brackets. The real and complex K-theory spectra serve as our main examples.

球面第24同伦群中的关系

Relations in the 24-th homotopy groups of spheres

本文证明了Toda括号⟨ν̄,σ,ν̄⟩和⟨ν,η,σ̄⟩非平凡，肯定了Mahowald猜想，并确定了π^6_{30}中ν̄_6ω_{14}和π^7_{31}中ν̄_7ω_{15}的关系。

Relations in the 24-th homotopy groups of spheres

The main purpose of this note is to give a proof of the fact that the Toda brackets $<\barν,σ,\barν>$ and $<ν,η, \barσ>$ are not trivial. This is an affirmative answer of the second author's Conjecture (Determination of the $P$-image by Toda brackets, Geometry and Topology Monographs 13(2008), 355-383). The second purpose is to show the relation $\barν_7ω_{15}=ν_7σ_{10}κ_{17}$ in $π^7_{31}$.

The strong Kervaire invariant problem in dimension 62

Using a Toda bracket computation $\langle θ_4, 2, σ^2\rangle$ due to Daniel C. Isaksen [11], we investigate the $45$-stem more thoroughly. We prove that $θ_4^2=0$ using a $4$-fold Toda bracket. By [2], this implies that $θ_5$ exists and there exists a $θ_5$ such that $2θ_5=0$. Based on $θ_4^2=0$, we simplify significantly the $9$-cell complex construction in [1] to a $4$-cell complex, which leads to another proof that $θ_5$ exists.

Harmonic spinors and metrics of positive curvature via the Gromoll filtration and Toda brackets

We construct non-trivial elements of order 2 in the homotopy groups $π_{8j+1+*} Diff(D^6,\partial)$, for * congruent 1 or 2 modulo 8, which are detected by the "assembling homomorphism" (giving rise to the Gromoll filtration), followed by the alpha-invariant in $KO_*=Z/2$. These elements are constructed by means of Morlet's homotopy equivalence between $Diff(D^6,\partial)$ and $Ω^7(PL_6/O_6)$, and Toda brackets in $PL_6/O_6$. We also construct non-trivial elements of order 2 in $π_* PL_m$ for every m greater or equal to 6 and * congruent to 1 or 2 modulo 8, which are detected by the alpha-inva…