Malkiewich, Cary; Merling, Mona Coassembly is a homotopy limit map. (English) Zbl 1452.55011 Ann. \(K\)-Theory 5, No. 3, 373-394 (2020). Let \(G\) be a group that is the realization of a simplicial group and \(X\) a \(G\)-spectrum. The homotopy limit map is defined as the map \(X^{G}\to X^{hG}\) from fixed points to homotopy fixed points. There are several instances where this appears and it is a basic question when this is an equivalence. On the other hand, given a reduced contravariant homotopy functor \(F\) on the comma category over \(BG\) to spectra, the coassembly map is a natural transformation \(F\to F_{\%}\) where \(F_{\%}\) is a suitable final object and has the universal property of approximating \(F\) by a functor that sends homotopy pushouts to homotopy pullbacks. The main theorem of this work is the following: Theorem A. Let \(G\) be a group as before. Then the coassembly map on the terminal object \(F(BG)\to F_{\%}(BG)\) is equivalent to the homotopy limit map of the \(G\) spectrum \(F(BG)\to F(BG)^{hG}\). As an application, the authors prove that the homotopy limit map for \(A_{G}^{coarse}(X)\) is isomorphic to the coassembly map for bivariant \(A\)-theory. Reviewer: Daniel Juan Pineda (Michoacan) Cited in 1 Document MSC: 55P42 Stable homotopy theory, spectra 19D10 Algebraic \(K\)-theory of spaces 55P91 Equivariant homotopy theory in algebraic topology Keywords:coassembly; \(A\)-theory; equivariant \(A\)-theory; homotopy limit; bivariant \(A\)-theory PDF BibTeX XML Cite \textit{C. Malkiewich} and \textit{M. Merling}, Ann. \(K\)-Theory 5, No. 3, 373--394 (2020; Zbl 1452.55011) Full Text: DOI arXiv OpenURL References: [1] 10.2140/gt.2018.22.3761 · Zbl 1409.55013 [2] 10.2140/tunis.2020.2.97 · Zbl 1461.18009 [3] 10.1007/978-3-540-38117-4 [4] 10.4310/HHA.2009.v11.n1.a2 · Zbl 1160.55005 [5] 10.1023/A:1007784106877 · Zbl 0921.19003 [6] 10.1016/S0040-9383(03)00029-6 · Zbl 1047.55004 [7] 10.1007/BF02393236 · Zbl 1077.19002 [8] 10.2307/2152801 · Zbl 0798.57018 [9] 10.1007/978-3-0346-0189-4 · Zbl 1195.55001 [10] 10.2140/gt.1999.3.103 · Zbl 0927.57028 [11] 10.1007/BFb0080003 [12] 10.1007/s00208-003-0454-5 · Zbl 1051.19002 [13] 10.1016/j.aim.2011.05.019 · Zbl 1247.14020 [14] 10.1007/BF01228231 · Zbl 0274.55008 [15] 10.1112/jtopol/jtv003 · Zbl 1373.55012 [16] 10.1016/j.aim.2016.11.017 · Zbl 1360.19001 [17] 10.25537/dm.2019v24.815-855 · Zbl 1423.19003 [18] 10.1112/S0024611501012692 · Zbl 1017.55004 [19] 10.1090/surv/132 [20] 10.1016/0022-4049(86)90094-0 · Zbl 0625.57024 [21] 10.2140/agt.2014.14.299 · Zbl 1299.19001 [22] 10.1017/CBO9781107261457 · Zbl 1317.18001 [23] 10.25537/dm.2018v23.1405-1424 · Zbl 1423.14157 [24] 10.1090/conm/019 · Zbl 0508.00006 [25] 10.1007/BFb0074449 [26] 10.2140/gt.1999.3.67 · Zbl 0927.57027 [27] 10.1017/CBO9780511629365.014 [28] 10.1090/conm/258/1778119 This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. It attempts to reflect the references listed in the original paper as accurately as possible without claiming the completeness or perfect precision of the matching.