Direct factor over central subgroup

From Groupprops

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This article defines a subgroup property: a property that can be evaluated to true/false given a group and a subgroup thereof, invariant under subgroup equivalence. View a complete list of subgroup properties[SHOW MORE]

Definition

Definition with symbols

Suppose is a subgroup of a group . We say that is a direct factor over central subgroup of if it satisfies the following equivalent conditions:

  1. There exists a subgroup of such that is a central subgroup of and is a direct factor of the quotient group .
  2. In the quotient map , where is the center of , is a direct factor of .

Relation with other properties

Stronger properties

property quick description proof of implication proof of strictness (reverse implication failure) intermediate notions
Direct factor |FULL LIST, MORE INFO
Central subgroup |FULL LIST, MORE INFO
Join of direct factor and central subgroup |FULL LIST, MORE INFO

Weaker properties

property quick description proof of implication proof of strictness (reverse implication failure) intermediate notions
Normal subgroup