scholarly journals Simple groups of Morley rank $3$ are algebraic

2017 ◽  
Vol 31 (3) ◽  
pp. 643-659 ◽  
Author(s):  
Olivier Frécon
Keyword(s):  
Simple Groups ◽  
Morley Rank

scholarly journals Tame minimal simple groups of finite Morley rank

2004 ◽  
Vol 276 (1) ◽  
pp. 13-79 ◽  
Author(s):  
Gregory Cherlin ◽  
Eric Jaligot
Keyword(s):  
Simple Groups ◽  
Morley Rank ◽  
Finite Morley Rank

On solvable centerless groups of Morley rank 3

1993 ◽  
Vol 58 (2) ◽  
pp. 546-556
Author(s):  
Mark Kelly Davis ◽  
Ali Nesin
Keyword(s):  
Nilpotent Group ◽  
General Structure ◽  
Nilpotent Groups ◽  
Simple Groups ◽  
Closed Field ◽  
Morley Rank ◽  
Nonnilpotent Group ◽  
Finite Morley Rank ◽  
Torsion Free Subgroup ◽  
Torsion Free

We know quite a lot about the general structure of ω-stable solvable centerless groups of finite Morley rank. Abelian groups of finite Morley rank are also well-understood. By comparison, nonabelian nilpotent groups are a mystery except for the following general results:• An ω1-categorical torsion-free nonabelian nilpotent group is an algebraic group over an algebraically closed field of characteristic 0 [Z3].• A nilpotent group of finite Morley rank is the central product of a definable subgroup of finite exponent and of a definable divisible subgroup [N3].• A divisible nilpotent group of finite Morley rank is the direct product of its torsion part (which is central) and of a torsion-free subgroup [N3].However, we do not understand nilpotent groups of bounded exponent. It seems that the classification of nilpotent (but nonabelian) p-groups of finite Morley rank is impossible. Even the nilpotent groups of Morley rank 2 contain insurmountable difficulties [C], [T] . At first glance, this may seem to be an obstacle to proving the Cherlin-Zil'ber conjecture (“simple groups of finite Morley rank are algebraic groups”). Our purpose in this article is to show that if such a group is a definable subgroup of a nonnilpotent group, then it is possible to obtain a classification within the boundaries of our present knowledge. In this respect, our article may be considered as a relief to those who are trying to classify simple groups of finite Morley rank.Before explicitly stating our result, we need the following definition.

scholarly journals Minimal connected simple groups of finite Morley rank with strongly embedded subgroups

2007 ◽  
Vol 314 (2) ◽  
pp. 581-612 ◽  
Author(s):  
Jeffrey Burdges ◽  
Gregory Cherlin ◽  
Eric Jaligot
Keyword(s):  
Simple Groups ◽  
Morley Rank ◽  
Finite Morley Rank

Groups of finite Morley rank with transitive group automorphisms

1989 ◽  
Vol 54 (3) ◽  
pp. 1080-1082
Author(s):  
Ali Nesin
Keyword(s):  
Finite Order ◽  
Short Note ◽  
Algebraic Groups ◽  
Transitive Group ◽  
Simple Groups ◽  
Morley Rank ◽  
Nontrivial Center ◽  
Finite Morley Rank ◽  
Group Automorphisms

The aim of this short note is to prove the following result:Theorem. Let G be a group of finite Morley rank with Aut G acting transitively on G/{1}. Then G is either abelian or a bad group.Bad groups were first defined by Cherlin [Ch]: these are groups of finite Morley rank without solvable and nonnilpotent connected subgroups. They have been investigated by the author [Ne 1], Borovik [Bo], Corredor [Co], and Poizat and Borovik [Bo-Po]. They are not supposed to exist, but we are far from proving their nonexistence. This is one of the major obstacles to proving Cherlin's conjecture: infinite simple groups of finite Morley rank are algebraic groups.If the group G of the theorem is finite, then it is well known that G ≈ ⊕Zp for some prime p: clearly all elements of G have the same order, say p, a prime. Thus G is a finite p-group, so has a nontrivial center. But Aut G acts transitively; thus G is abelian. Since it has exponent p, G ≈ ⊕Zp.The same proof for infinite G does not work even if it has finite Morley rank, for the following reasons:1) G may not contain an element of finite order.2) Even if G does contain an element of finite order, i.e. if G has exponent p, we do not know if G must have a nontrivial center.

The uniqueness of envelopes in ℵ0-categorical, ℵ0-stable structures

1984 ◽  
Vol 49 (4) ◽  
pp. 1171-1184 ◽  
Author(s):  
James Loveys
Keyword(s):  
Group Theory ◽  
Finite Subset ◽  
Classification Theorem ◽  
Simple Groups ◽  
Finite Model ◽  
Finite Simple Groups ◽  
Morley Rank ◽  
Categorical Theory ◽  
Rank 2 ◽  
Stable Structures

The Classification Theorem for ℵ0-categorical strictly minimal sets says that if H is strictly minimal and ℵ0-categorical, either H has in effect no structure at all or is essentially an affine or projective space over a finite field. Zil′ber, in [Z2], showed that if H were a counterexample to this Classification Theorem it would interpret a rank 2, degree 1 pseudoplane. Cherlin later noticed (see [CHL, Appendices 2 and 3], for the proof) that the Classification Theorem is a consequence of the Classification Theorem for finite simple groups. In [Z4] and [Z5], Zil′ber found a quite different proof of the Classification Theorem using no deep group theory.Meanwhile in [Z3], Zil′ber introduced the notion of envelope in an attempt to prove that no complete totally categorical theory T can be finitely axiomatizable. The idea of the proof was to show that if M is a model of such a T and H ⊆ M is strongly minimal, then an envelope of any sufficiently large finite subset of H is a finite model of any fixed finite subset of T. [Z3] contains an error, which Zil′ber has since corrected (in a nontrivial way).In [CHL], Cherlin, Harrington and Lachlan used the Classification Theorem to expand and reorganize Zil′ber's work. In particular, they generalized most of his work to ℵ0-categorical, ℵ0-stable structures, proved the Morley rank is finite in these structures, and introduced the powerful Coordinatization Theorem (Theorem 3.1 of [CHL]; Proposition 1.14 of the present paper). They also showed that ℵ0-categorical, ℵ0-stable structures are not finitely axiomatizable using a notion of envelope that is the same as Zil′ber's except in one particularly perverse case; [CHL]'s notion of envelope is used throughout the current paper. Peretyat'kin [P] has found an example of an ℵ1-categorical finitely axiomatizable structure.

scholarly journals CONJUGACY OF CARTER SUBGROUPS IN GROUPS OF FINITE MORLEY RANK

2008 ◽  
Vol 08 (01) ◽  
pp. 41-92 ◽  
Author(s):  
OLIVIER FRÉCON
Keyword(s):  
Conjugacy Class ◽  
Algebraic Groups ◽  
Simple Groups ◽  
Morley Rank ◽  
Minimal Counterexample ◽  
Finite Morley Rank ◽  
Cartan Subgroups

The Cherlin–Zil'ber Conjecture states that all simple groups of finite Morley rank are algebraic. We prove that any minimal counterexample to this conjecture has a unique conjugacy class of Carter subgroups, which are analogous to Cartan subgroups in algebraic groups.

scholarly journals Structure of Borel subgroups in simple groups of finite Morley rank

2015 ◽  
Vol 208 (1) ◽  
pp. 101-162
Author(s):  
Tuna Altinel ◽  
Jeffrey Burdges ◽  
Olivier Frécon
Keyword(s):  
Simple Groups ◽  
Morley Rank ◽  
Finite Morley Rank

Full Frobenius Groups of Finite Morley Rank and the Feit-Thompson Theorem

2001 ◽  
Vol 7 (3) ◽  
pp. 315-328 ◽  
Author(s):  
Eric Jaligot
Keyword(s):  
Frobenius Group ◽  
Major Obstacle ◽  
Simple Groups ◽  
Morley Rank ◽  
Frobenius Groups ◽  
Finite Morley Rank

AbstractWe show how the notion of full Frobenius group of finite Morley rank generalizes that of bad group, and how it seems to be more appropriate when we consider the possible existence (still unknown) of nonalgebraic simple groups of finite Morley rank of a certain type, notably with no involution. We also show how these groups appear as a major obstacle in the analysis of FT-groups, if one tries to extend the Feit-Thompson theorem to groups of finite Morley rank.

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