Higher colimits, derived functors and homology. / Ivanov, S. O.; Mikhailov, R. V.; Sosnilo, V. A.
In: Sbornik Mathematics, Vol. 210, No. 9, 09.2019, p. 1222-1258.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Higher colimits, derived functors and homology
AU - Ivanov, S. O.
AU - Mikhailov, R. V.
AU - Sosnilo, V. A.
PY - 2019/9
Y1 - 2019/9
N2 - We develop a theory of higher colimits over categories of free presentations. We show that different homology functors such as Hochschild and cyclic homology of algebras over a field of characteristic zero, simplicial derived functors, and group homology can be obtained as higher colimits of simply defined functors. Connes’ exact sequence linking Hochschild and cyclic homology was obtained using this approach as a corollary of a simple short exact sequence. As an application of the developed theory, we show that the third reduced K-functor can be defined as the colimit of the second reduced K-functor applied to the fibre square of a free presentation of an algebra. We also prove a Hopf-type formula for odd-dimensional cyclic homology of an algebra over a field of characteristic zero.
AB - We develop a theory of higher colimits over categories of free presentations. We show that different homology functors such as Hochschild and cyclic homology of algebras over a field of characteristic zero, simplicial derived functors, and group homology can be obtained as higher colimits of simply defined functors. Connes’ exact sequence linking Hochschild and cyclic homology was obtained using this approach as a corollary of a simple short exact sequence. As an application of the developed theory, we show that the third reduced K-functor can be defined as the colimit of the second reduced K-functor applied to the fibre square of a free presentation of an algebra. We also prove a Hopf-type formula for odd-dimensional cyclic homology of an algebra over a field of characteristic zero.
KW - Cyclic homology
KW - Derived functors
KW - Higher colimits
KW - K-theory
UR - http://www.scopus.com/inward/record.url?scp=85087453356&partnerID=8YFLogxK
U2 - 10.1070/SM9152
DO - 10.1070/SM9152
M3 - Article
AN - SCOPUS:85087453356
VL - 210
SP - 1222
EP - 1258
JO - Sbornik Mathematics
JF - Sbornik Mathematics
SN - 1064-5616
IS - 9
ER -
ID: 62108185