TY - EJOUR
DO - 10.1007/s13348-013-0102-7
AB - Consider a fibration sequence of topological spaces which is preserved as such by some functor , so that is again a fibration sequence. Pull the fibration back along an arbitrary map into the base space. Does the pullback fibration enjoy the same property? For most functors this is not to be expected, and we concentrate mostly on homotopical localization functors. We prove that the only homotopical localization functors which behave well under pull-backs are nullifications. The same question makes sense in other categories. We are interested in groups and how localization functors behave with respect to group extensions. We prove that group theoretical nullification functors behave nicely, and so do all epireflections arising from a variety of groups.
T1 - Conditionally flat functors on spaces and groups
IS - 1
DA - 2015
AU - Farjoun, Emmanuel Dror
AU - Scherer, Jerome
JF - Collectanea Mathematica
SP - 149-160
VL - 66
EP - 149-160
PB - Springer-Verlag Italia Srl
PP - Milan
ID - 205398
KW - Localization
KW - Flatness
KW - Fiberwise localization
KW - Variety of groups
SN - 0010-0757
ER -