
doi: 10.1007/bf01078391
In recent years many new (co)homology theories of (non)commutative (operator) algebras have been discovered: The homological \(K\)-functor Ext of \textit{L. G. Brown}, \textit{R. G. Douglas} and \textit{P. A. Fillmore} [see Bull. Am. Math. Soc. 79, 973--978 (1973; Zbl 0277.46052)] having after all some interesting application in the structure theory of \(C^*\)-algebras [see the reviewer, Funkts. Anal. Prilozh. 9, No. 1, 63--64 (1975; Zbl 0347.46068)], Kasparov's \(KK\)-functor [see \textit{G. G. Kasparov}, Izv. Akad. Nauk SSSR, Ser. Mat. 44, 571--636 (1980; Zbl 0448.46051)], Connes' cyclic homology \(HC\)-functor [see \textit{M. Karoubi}, C. R. Acad. Sci., Paris, Sér. I 297, 381--384, 447--450, 513--516, 557--560 (1983; Zbl 0528.18008, Zbl 0528.18009, Zbl 0528.18010, Zbl 0532.18009)], and the Gel'fand-Fuks cohomology theory of infinite-dimensional Lie algebras. The most important point in these developments is replacing the structural function sheaf by an arbitrary (non)commutative algebra. The paper under review is a new account of this fact, where the algebra of functions on a manifold is replaced by a (non)commutative algebra. One considers for each algebra \(A\) over a field \(K\) of characteristic zero the standard bimodule resolution \[ R_* :\quad... \to A\otimes A\otimes A\to^{\delta}A\otimes A\to^{\delta}A\to 0 \] with the differential \(\delta (a_ 1\otimes...\otimes a_ k)=\sum^{k-1}_{i=1}(-1)^ ia_ i\otimes...\otimes a_ ia_{i+1}\otimes...ca_ k\), the standard complex \(C_*(A)\) of the Lie algebra \(\mathfrak{gl}_{\infty}(A)\) of infinite matrices of finite type over \(A\) with coefficients in the unit module, and finally a complex homomorphism \[ \phi: C_*(A)\to (R_*,\delta),\quad \phi ((m_ 1\otimes a_ 1)\wedge...\wedge (m_ k\otimes a_ k))=\sum_{i}\text{sgn}(i)\text{tr}(m_{i_ 1}...m_{i_ k}) a_{i_ 1}\otimes...\otimes a_{i_ k}. \] The image of \(\phi\) is the subcomplex \(\bar R_*\subset R_*\) consisting of chains that are invariant under the transfer map \(t\), \(t(a_ 1\otimes...\otimes a_ k)=(- 1)^{k-1}a_ k\otimes a_ 1\otimes...\otimes a_{k-1}\). Via \(\phi\), the additive \(K\)-functor group \[ K^+_*(A)=\lim_{\leftarrow} H_*(\mathfrak{gl}_{\infty}(A),K) \] is isomorphic [\textit{J.-L. Loday} and \textit{D. Quillen}, C. R. Acad. Sci. Paris, Sér. I 296, 295--297 (1983; Zbl 0536.17006); \textit{B. L. Tsygan}, Usp. Mat. Nauk 38, No. 2 (230), 217--218 (1983; Zbl 0518.17002)] to Connes' cyclic cohomology group \(HC^*(A)=H_*(\bar R_*,\delta).\) The authors show that \(K^+_*(A)\) are the higher derived functors of the functor \(K^+_ 1\) in the category of algebras: \[ K^+_ 1(R)\simeq R/[R,R],\quad H_*(R/[R,R])\simeq \lim_{\leftarrow} H_*(\mathfrak{gl}_{\infty}(A),\mathfrak{gl}_{\infty}(K);K). \] On the category of arrows \(A\to^{f}B\) one defines (Th. 1) the relative additive \(K^+\)-functor \(K^+_*(B,A)\) as the derived functors of \(K^+_ 0(B,A)=B/([B,B]+\text{Im}\, f)\). One has (Th. 2) an exact sequence \[ ... \to K^+_{i+1}(C,B) \to K^+_ i(B,A) \to K^+_ i\quad (C,A) \to K^+_ i(C,B) \to... \] associated with the pair of arrows \(A\to^{f}B\to^{g}C.\) The authors propose also (in Section 2) a construction independent from the Connes-Karoubi one of the Chern characters \(Ch: K_ n(A)\to K^+_{n+2i+1}(A)\), \(i\in\mathbb Z_+\). Then, the Bott periodicity morphism \(K^+_ i(A)\to K^+_{i-2}(A)\) exists, and hence, the groups \(K^+_ i\) with i of fixed parity form an inverse system. The authors define the cohomology of an algebra \(A\) as \[ H^{\text{odd}}(A)=\lim_{\leftarrow}K^+_{2i}(A) \oplus R^ 1\lim_{\leftarrow}K^+_{2i+1}(A),\quad H^{\text{ev}}(A)=\lim_{\leftarrow}K^+_{2i+1}(A) \oplus R^ 1\lim_{\leftarrow}K^+_{2i\quad}(A). \] In the case where \(A\) is commutative (Section 3), \(H^{\text{odd}}(A)+H^{\text{ev}}(A)\) is isomorphic to the crystalline cohomology of the spectrum of A and there exists a morphism \[ K^+_ n(A)\to \oplus_{N}H^*(X_{\text{cris}}, \mathcal O_ X/J^ N). \] If \(R\) is a free commutative differential graded algebra for which there exists an epimorphic quasiisomorphism \(R\to A\) the authors consider the de Rham complex \(R: R\to^{d}\Omega^ 1_ R\quad \to \quad...\) and prove that \(K^+_*(A,K)\simeq H_*(\Omega^*_ R/(K+d\Omega^*_ R))\). This just coincides with Connes' result in the case where \(\text{Spec}\,A\) is a nonsingular variety.
Homology and homotopy of \(B\mathrm{O}\) and \(B\mathrm{U}\); Bott periodicity, Ext and \(K\)-homology, Classifying spaces for foliations; Gelfand-Fuks cohomology, Resolutions; derived functors (category-theoretic aspects), Categories, functors in functional analysis, \(p\)-adic cohomology, crystalline cohomology, cohomology theories of noncommutative operator algebras, Continuous cohomology of Lie groups, Topological \(K\)-theory, Kasparov's KK-functor, \(K\)-theory and operator algebras, homological K-functor, additive K-functor, Lie, Kasparov theory (\(KK\)-theory), derived functors, Graded rings and modules (associative rings and algebras), cyclic homology, \(K\)-theory and operator algebras (including cyclic theory), Cohomology of Lie (super)algebras, crystalline cohomology, algebras, Chern characters, differential graded algebra, de Rham complex, Homology of classifying spaces and characteristic classes in algebraic topology, \(C^*\)-algebras, Gel'fand-Fuks cohomology theory of infinite-dimensional Lie, Algebraic \(K\)-theory and \(L\)-theory (category-theoretic aspects), algebra of infinite matrices of finite type, Bott periodicity, Gel'fand-Fuks cohomology theory of infinite-dimensional Lie algebras, Methods of algebraic topology in functional analysis (cohomology, sheaf and bundle theory, etc.)
Homology and homotopy of \(B\mathrm{O}\) and \(B\mathrm{U}\); Bott periodicity, Ext and \(K\)-homology, Classifying spaces for foliations; Gelfand-Fuks cohomology, Resolutions; derived functors (category-theoretic aspects), Categories, functors in functional analysis, \(p\)-adic cohomology, crystalline cohomology, cohomology theories of noncommutative operator algebras, Continuous cohomology of Lie groups, Topological \(K\)-theory, Kasparov's KK-functor, \(K\)-theory and operator algebras, homological K-functor, additive K-functor, Lie, Kasparov theory (\(KK\)-theory), derived functors, Graded rings and modules (associative rings and algebras), cyclic homology, \(K\)-theory and operator algebras (including cyclic theory), Cohomology of Lie (super)algebras, crystalline cohomology, algebras, Chern characters, differential graded algebra, de Rham complex, Homology of classifying spaces and characteristic classes in algebraic topology, \(C^*\)-algebras, Gel'fand-Fuks cohomology theory of infinite-dimensional Lie, Algebraic \(K\)-theory and \(L\)-theory (category-theoretic aspects), algebra of infinite matrices of finite type, Bott periodicity, Gel'fand-Fuks cohomology theory of infinite-dimensional Lie algebras, Methods of algebraic topology in functional analysis (cohomology, sheaf and bundle theory, etc.)
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