Stable group

For stable groups in homotopy theory see stable homotopy group or direct limit of groups.
For stable groups in finite group theory, see p-stable group.

In model theory, a stable group is a group that is stable in the sense of stability theory. An important class of examples is provided by groups of finite Morley rank (see below).

Examples

The Cherlin–Zilber conjecture

The Cherlin–Zilber conjecture (also called the algebraicity conjecture), due to Gregory Cherlin (1979) and Boris Zilber (1977), suggests that infinite (ω-stable) simple groups are simple algebraic groups over algebraically closed fields. The conjecture would have followed from Zilber trichotomy conjecture. Cherlin posed the question for all ω-stable simple groups, but remarked that even the case of groups of finite Morley rank seemed hard.

Progress towards this conjecture has followed Borovik’s program of transferring methods used in classification of finite simple groups. One possible source of counterexamples is bad groups: nonsoluble connected groups of finite Morley rank all of whose proper connected definable subgroups are nilpotent, (A group is called connected if it has no definable subgroups of finite index other than itself.)

A number of special cases of this conjecture have been proved; for example:

References

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