For a profinite group
,
let
,
and
denote continuous homotopy fixed points for profinite
–spectra, discrete
–spectra and continuous
–spectra (coming from
towers of discrete
–spectra),
respectively. We establish some connections between the first two notions, and by using Postnikov
towers, for
(a
closed normal subgroup), we give various conditions for when the iterated homotopy fixed points
exist and are
. For the Lubin–Tate
spectrum
and
,
the extended Morava stabilizer group, our results show that
is a profinite
–spectrum with
; we achieve this
by an argument that possesses a certain technical simplicity enjoyed by neither the proof that
nor the Devinatz–Hopkins
proof (which requires
)
of
, where
is a construction
that behaves like continuous homotopy fixed points. Also, we prove that (in general) the
–homotopy fixed point
spectral sequence for
,
with
(continuous cohomology), is isomorphic to both the strongly
convergent Lyndon–Hochschild–Serre spectral sequence of Devinatz for
and the descent
spectral sequence for
.
Keywords
profinite $G$–spectrum, homotopy fixed point spectrum,
iterated homotopy fixed point spectrum, Lubin–Tate
spectrum, descent spectral sequence