ترغب بنشر مسار تعليمي؟ اضغط هنا

A lift from group cohomology to spectra for trivial profinite actions

62   0   0.0 ( 0 )
 نشر من قبل Daniel Davis
 تاريخ النشر 2019
  مجال البحث
والبحث باللغة English
 تأليف Daniel G. Davis




اسأل ChatGPT حول البحث

Let $G$ be a profinite group, $X$ a discrete $G$-spectrum with trivial action, and $X^{hG}$ the continuous homotopy fixed points. For any $N trianglelefteq_o G$ ($o$ for open), $X = X^N$ is a $G/N$-spectrum with trivial action. We construct a zigzag $text{colim},_N ,X^{hG/N} buildrelPhioverlongrightarrow text{colim},_N ,(X^{hN})^{hG/N} buildrelPsioverlongleftarrow X^{hG}$, where $Psi$ is a weak equivalence. When $Phi$ is a weak equivalence, this zigzag gives an interesting model for $X^{hG}$ (for example, its Spanier-Whitehead dual is $text{holim},_N ,F(X^{hG/N}, S^0)$). We prove that this happens in the following cases: (1) $|G| < infty$; (2) $X$ is bounded above; (3) there exists ${U}$ cofinal in ${N}$, such that for each $U$, $H^s_c(U, pi_ast(X)) = 0$, for $s > 0$. Given (3), for each $U$, there is a weak equivalence $X buildrelsimeqoverlongrightarrow X^{hU}$ and $X^{hG} simeq X^{hG/U}$. For case (3), we give a series of corollaries and examples. As one instance of a family of examples, if $p$ is a prime, $K(n_p,p)$ the $n_p$th Morava $K$-theory $K(n_p)$ at $p$ for some $n_p geq 1$, and $mathbb{Z}_p$ the $p$-adic integers, then for each $m geq 2$, (3) is satisfied when $G leqslant prod_{p leq m} mathbb{Z}_p$ is closed, $X = bigvee_{p > m} (Hmathbb{Q} vee K(n_p,p))$, and ${U} := {N_G mid N_G trianglelefteq_o G}$.



قيم البحث

اقرأ أيضاً

88 - Danny Sugrue 2019
In this thesis we will investigate rational G-spectra for a profinite group G. We will provide an algebraic model for this model category whose injective dimension can be calculated in terms of the Cantor-Bendixson rank of the space of closed subgrou ps of G, denoted SG. The algebraic model we consider is chain complexes of Weyl-G-sheaves of rational vector spaces over the spaces. The key step in proving that this is an algebraic model for G-spectra is in proving that the category of rational G-Mackey functors is equivalent to Weyl-G-sheaves. In addition to the fact that this sheaf description utilises the topology of G and the closed subgroups of G in a more explicit way than Mackey functors do, we can also calculate the injective dimension. In the final part of the thesis we will see that the injective dimension of the category of Weyl-G-sheaves can be calculated in terms of the Cantor-Bendixson rank of SG, hence giving the injective dimension of the category of Mackey functors via the earlier equivalence.
This survey paper describes two geometric representations of the permutation group using the tools of toric topology. These actions are extremely useful for computational problems in Schubert calculus. The (torus) equivariant cohomology of the flag v ariety is constructed using the combinatorial description of Goresky-Kottwitz-MacPherson, discussed in detail. Two permutation representations on equivariant and ordinary cohomology are identified in terms of irreducible representations of the permutation group. We show how to use the permutation actions to construct divided difference operators and to give formulas for some localizations of certain equivariant classes. This paper includes several new results, in particular a new proof of the Chevalley-Monk formula and a proof that one of the natural permutation representations on the equivariant cohomology of the flag variety is the regular representation. Many examples, exercises, and open questions are provided.
165 - Sebastian Thomas 2009
We give an algebraic proof for the result of Eilenberg and Mac Lane that the second cohomology group of a simplicial group G can be computed as a quotient of a fibre product involving the first two homotopy groups and the first Postnikov invariant of G. Our main tool is the theory of crossed module extensions of groups.
This paper is a continuations of the project initiated in the book string topology for stacks. We construct string operations on the SO(2)-equivariant homology of the (free) loop space $L(X)$ of an oriented differentiable stack $X$ and show that $H^{ SO(2)}_{*+dim(X) -2}(L(X))$ is a graded Lie algebra. In the particular case where $X$ is a 2-dimensional orbifold we give a Goldman-type description for the string bracket. To prove these results, we develop a machinery of (weak) group actions on topological stacks which should be of independent interest. We explicitly construct the quotient stack of a group acting on a stack and show that it is a topological stack. Then use its homotopy type to define equivariant (co)homology for stacks, transfer maps, and so on.
Let E be a k-local profinite G-Galois extension of an E_infty-ring spectrum A (in the sense of Rognes). We show that E may be regarded as producing a discrete G-spectrum. Also, we prove that if E is a profaithful k-local profinite extension which sat isfies certain extra conditions, then the forward direction of Rogness Galois correspondence extends to the profinite setting. We show the function spectrum F_A((E^hH)_k, (E^hK)_k) is equivalent to the homotopy fixed point spectrum ((E[[G/H]])^hK)_k where H and K are closed subgroups of G. Applications to Morava E-theory are given, including showing that the homotopy fixed points defined by Devinatz and Hopkins for closed subgroups of the extended Morava stabilizer group agree with those defined with respect to a continuous action and in terms of the derived functor of fixed points.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا