TY - JOUR
T1 - Bounding Topology via Geometry, $A$-Simple Fundamental Groups
AU - Rong , Xiaochun
AU - Yao , Xuchao
JO - Communications in Mathematical Research 
VL - 4
SP - 489
EP - 505
PY - 2020
DA - 2020/11
SN - 36
DO - http://doi.org/10.4208/cmr.2020-0030
UR - https://global-sci.org/intro/article_detail/cmr/18363.html
KW - $A$-simple fundamental group, collapsing with bounded sectional curvature, finiteness of fundamental groups and diffeomorphic types.
AB - <p style="text-align: justify;">We call a group $A$-simple, if it has no non-trivial normal abelian sub-group. We will present finiteness results in controlled topology via geometry
on manifolds whose fundamental groups are $A$-simple.</p>