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Feb 24, 2016 at 16:32 vote accept Jonathan Beardsley
Feb 24, 2016 at 16:32 answer added Jonathan Beardsley timeline score: 1
Dec 1, 2014 at 0:48 history edited Jonathan Beardsley CC BY-SA 3.0
fixed a minor error in notation
Nov 14, 2014 at 14:11 comment added Jonathan Beardsley I should perhaps also add that in certain nice cases I have been able to work this out (the write-ups are on my website). But that relies on the collapse of a certain Kunneth spectral sequence which seems unlikely in general. It would be nice to have more general conditions.
May 30, 2014 at 14:57 comment added Jonathan Beardsley I should also mention that that convergence I mention definitely holds for a LOT of interesting Thom spectra: $MU$, $MSO$, $MSU$, $X(n)$, Baker and Richter's $M\xi$. And the alternate situation (being an extension of the 2-adic sphere spectrum) holds for $MO$.
May 30, 2014 at 14:07 comment added Jonathan Beardsley Ah thanks @JustinNoel I had seen that word (primitives) used in some places. Perhaps it will be less confusing if I start using that rather than cofixed points.
May 30, 2014 at 11:53 comment added Justin Noel I would like to point out that $Mf$ being $\mathbb{Z}$-orientable is not a very severe restriction and follows from $G$ being simply connected. The condition is equivalent to $f$ lifting to the simply connected cover $BSL_1 S$ of $BGL_1 S$. Assuming your Hopf-Galois condition is essentially the convergence of the associated Adams spectral sequence, when $Mf$ is not $\mathbb{Z}$-orientable then you obtain a Hopf-Galois extension of the 2-adic sphere spectrum. Also in the algebraic context of coactions, what you are calling cofixed points are traditionally called primitives.
May 30, 2014 at 0:47 history edited Jonathan Beardsley
edited tags
May 30, 2014 at 0:29 history asked Jonathan Beardsley CC BY-SA 3.0