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A possibly interesting analogue of the formula $H\mathbb{F}_{2*} H\mathbb{F}_2 = \otimes_{i\ge1} \mathbb{F}_2[\xi_i]$ is $H\mathbb{Z}_{(2)*} H\mathbb{Z}_{(2)} = \bigotimes^\mathbb{L}_{i\ge1} \mathbb{ …

The $A(2)$-module structure on $A(2)//A(1)$ does not extend to an $A$-module structure. In particular, there is no spectrum $X$ with $H^*(X; F_2) = A(2)//A(1)$ as an $A(2)$-module. Additively, $A(2) …

With the aid of machine computations, you can readily determine the Adams differentials up to $t-s=30$ using the multiplicative structure, the relation between Steenrod operations in $\text{Ext}_A$ an …

The $2$-completed stable $20$-stem $\pi_{20}(S)_2$ is cyclic of order $8$. Mimura and Toda (1963, Lemma 15.4) mr=157384 show the existence of a class $\bar\kappa_7 \in \pi_{27}(S^7)$ whose stable cla …

The $D$ with $D(xy) = xD(y) + D(x)y$ are the primitives in the Steenrod algebra $A$, which are dual to the indecomposables $\xi_i$ in $A_* = F_2[\xi_i \mid i\ge1]$, so there is one such $D$ in each de …

By May's Remark 2.6, the answer should be no. If $X$ is a Moore space with $\tilde H_*(X; Z) = Z/p$ concentrated in an odd degree $2q-1$, and $\tilde H_*(X; Z/p) = Z/p\{x, y\}$ with $\beta_1(y) = x$, …

A concise formula $$ \mu(\beta) = \beta(c(t^F)) $$ for the $BP_* BP$-coaction $\mu$ on $BP_* CP^\infty$ is given in the "Note added in proof" on page 279 of Ravenel, Douglas C.; Wilson, W. Stephen The …

I would say that the historically correct place to start is Quillen's letter to Milnor on the image of $(\pi_i O \to \pi_i^s \to K_i\mathbb{Z})$, published in Springer LNM 551 (1976). There Quillen pr …

Let me write $HH^S(B) = THH(B) = B \wedge_{B^e} B$ for topological Hochschild homology, and $HH_S(B) = F_{B^e}(B, B)$ for topological Hochschild cohomology, where $B^e = B \wedge_S B^{op}$. For $B$ c …

For $3$-primary homotopy of $S$ there is early work by Nakamura, Osamu Some differentials in the mod 3 Adams spectral sequence. Bull. Sci. Engrg. Div. Univ. Ryukyus Math. Natur. Sci. No. 19 (1975), 1– …

Let $R$ be bounded below, bounded above and nontrivial, and work in $R$-modules. Let $X = \bigvee_{n\in\mathbb{Z}} \Sigma^n R$. Then $X \overset{\simeq}\to D(DX)$ is an equivalence, but $X$ is not d …

The $E$-based Adams spectral sequence is the homotopy spectral sequence associated to the tower of spectra $\dots \to Y_2 \to Y_1 \to Y_0 = S$ with $Y_{s+1} \to Y_s \to E \wedge Y_s$ a homotopy fiber …

In the context of functors with smash product (FSP), or symmetric spectra, or orthogonal spectra, the spectrum with $\Sigma_2$-action $X \wedge X$ prolongs essentially uniquely to a $\Sigma_2$-spectru …

You can learn about this, and more, in Part II of Adams' "Stable Homotopy and Generalised Homology" (1974), especially section 4, in the special case $E = KU$.

Perhaps it helps to first think about how you can construct a map $\alpha_k : \Sigma^k S(\pi_k M) \to M$ inducing an isomorphism on $\pi_k$. Choose a free resolution $$ 0 \to \bigoplus_{j \in J} \mat …