Right exact group completion as a transfinite invariant of homology equivalence. / Ivanov, Sergei O.; Mikhailov, Roman.
In: Algebraic and Geometric Topology, Vol. 21, No. 1, 2021, p. 447-468.Research output: Contribution to journal › Article › peer-review
}
TY - JOUR
T1 - Right exact group completion as a transfinite invariant of homology equivalence
AU - Ivanov, Sergei O.
AU - Mikhailov, Roman
N1 - Publisher Copyright: © 2021, Mathematical Science Publishers. All rights reserved.
PY - 2021
Y1 - 2021
N2 - We consider a functor from the category of groups to itself, G → Z∞G, that we call right exact Z -completion of a group. It is connected with the pro-nilpotent completion G by the short exact sequence 1 → lim1 MnG → Z∞G → G → 1, where MnG is nth Baer invariant of G. We prove that Z00(µ1X) is an invariant of homological equivalence of a space X. Moreover, we prove an analogue of Stallings' theorem: If G → G0 is a 2-connected group homomorphism, then Z∞G ^ Z∞G'. We give examples of 3-manifolds X and Y such that n1X ^ 7r17 but Z1^1X
AB - We consider a functor from the category of groups to itself, G → Z∞G, that we call right exact Z -completion of a group. It is connected with the pro-nilpotent completion G by the short exact sequence 1 → lim1 MnG → Z∞G → G → 1, where MnG is nth Baer invariant of G. We prove that Z00(µ1X) is an invariant of homological equivalence of a space X. Moreover, we prove an analogue of Stallings' theorem: If G → G0 is a 2-connected group homomorphism, then Z∞G ^ Z∞G'. We give examples of 3-manifolds X and Y such that n1X ^ 7r17 but Z1^1X
UR - http://www.scopus.com/inward/record.url?scp=85103036649&partnerID=8YFLogxK
U2 - 10.2140/agt.2021.21.447
DO - 10.2140/agt.2021.21.447
M3 - Article
AN - SCOPUS:85103036649
VL - 21
SP - 447
EP - 468
JO - Algebraic and Geometric Topology
JF - Algebraic and Geometric Topology
SN - 1472-2747
IS - 1
ER -
ID: 90651015