Black box groups and related group theoretic constructions

Download
2007
Yalçınkaya, Şükrü
The present thesis aims to develop an analogy between the methods for recognizing a black box group and the classification of the finite simple groups. We propose a uniform approach for recognizing simple groups of Lie type which can be viewed as the computational version of the classification of the finite simple groups. Similar to the inductive argument on centralizers of involutions which plays a crucial role in the classification project, our approach is based on a recursive construction of the centralizers of involutions in black box groups. We present an algorithm which constructs a long root SL_2(q)-subgroup in a finite simple group of Lie type of odd characteristic $p$ extended possibly by a p-group. Following this construction, we take the Aschbacher's ``Classical Involution Theorem'' as a model in the final recognition algorithm and we propose an algorithm which constructs all root SL_2(q)-subgroups corresponding to the nodes in the extended Dynkin diagram, that is, our approach is the construction of the the extended Curtis - Phan - Tits presentation of the finite simple groups of Lie type of odd characteristic which further yields the construction of all subsystem subgroups which can be read from the extended Dynkin diagram. In this thesis, we present this algorithm for the groups PSL_n(q) and PSU_n(q). We also present an algorithm which determines whether the p-core (or ``unipotent radical'') O_p(G) of a black box group G is trivial or not where G/O_p(G) is a finite simple classical group of Lie type of odd characteristic p answering a well-known question of Babai and Shalev. The algorithms presented in this thesis have been implemented extensively in the computer algebra system GAP.

Suggestions

Descriptive complexity of subsets of the space of finitely generated groups
Benli, Mustafa Gökhan; Kaya, Burak (2022-12-01)
© 2022 Elsevier GmbHIn this paper, we determine the descriptive complexity of subsets of the Polish space of marked groups defined by various group theoretic properties. In particular, using Grigorchuk groups, we establish that the sets of solvable groups, groups of exponential growth and groups with decidable word problem are Σ20-complete and that the sets of periodic groups and groups of intermediate growth are Π20-complete. We also provide bounds for the descriptive complexity of simplicity, amenability,...
Hierarchical control with partial observations: Sufficient conditions
Boutin, Olivier; Komenda, Jan; Masopust, Tomas; Schmidt, Klaus Verner; Van Schuppen, Jan H. (2011-12-01)
In this paper, hierarchical control of both monolithic and modular discrete-event systems under partial observations is studied. Two new conditions, called observation consistency and local observation consistency, are proposed. These conditions are sufficient for the preservation of observability between the original and the abstracted plant. Moreover, it is shown that both conditions are compositional, that is, they are preserved by the synchronous product. This property makes it possible to use hierarchi...
A socio-spatial approach to the question of class and consciousness formation in a local setting: the case of Bursa industrial workers
Erengezgin, B Çavlan; Şengül, Hüseyin Tarık; Department of Urban Policy Planning and Local Governments (2007)
The aim of this thesis is to explore the class and consciousness formation in a local setting by also developing and applying a theoretical framework which allow us to study the interaction of locus of class consciousness with the other loci of consciousness formation such as the community and the state. Such an approach is also grounded in the belief that a relational understanding of these processes requires us to take spatial dynamics such as local dependency, spatial fix and fixity and mobility into acc...
Universal groups of intermediate growth and their invariant random subgroups
Benli, Mustafa Gökhan; Nagnibeda, Tatiana (2015-07-01)
We exhibit examples of groups of intermediate growth with ergodic continuous invariant random subgroups. The examples are the universal groups associated with a family of groups of intermediate growth.
Algebraic curves hermitian lattices and hypergeometric functions
Zeytin, Ayberk; Önsiper, Mustafa Hurşit; Department of Mathematics (2011)
The aim of this work is to study the interaction between two classical objects of mathematics: the modular group, and the absolute Galois group. The latter acts on the category of finite index subgroups of the modular group. However, it is a task out of reach do understand this action in this generality. We propose a lattice which parametrizes a certain system of ”geometric” elements in this category. This system is setwise invariant under the Galois action, and there is a hope that one can explicitly under...
Citation Formats
Ş. Yalçınkaya, “Black box groups and related group theoretic constructions,” Ph.D. - Doctoral Program, Middle East Technical University, 2007.