1,720,966 research outputs found
Baumann-components of finite groups of characteristic p, reduction theorems
No full textWe continue the project started in "Baumann-components of finite groups of characteristic p, general theory" to describe the structure of the finite groups G of characteristic p in terms of their Baumann components and the conjugacy class Baup(G). The reduction theorem proved in that paper allows to assume that G has a unique Baumann component. In this paper we use this property to determine the isomorphism type of G/Op(G) and the action of G on Ω1(Z(Op(G))). In addition, we prove reduction theorems which allow to focus on groups G which satisfy G/Op(G)≅SLn(q), Sp2n(q) or G2(q) and Op(G)⩽B for B∈Baup(G)
Baumann-components of finite groups of characteristic p, the W(B)-theorem
No full textThis paper completes the investigation of finite CK-groups of characteristic p in terms of their Baumann components we began in [Baumann-components of finite groups in characteristic p, general theory] and [Baumann-components of finite groups in characteristic p, reduction theorems]. In this paper we define for each finite p-group B a non-trivial characteristic subgroup W(B) and for each finite CK-group G of characteristic p with B in Baup(G), subnormal subgroups of G called Baumann blocks of G. We prove that G = N_G(W(B))E_W(G), where E_W(G) is the normal subgroup generated by the Baumann blocks of G. Moreover, we give the exact structure of the Baumann blocks of G and show that any two distinct Baumann blocks centralize each other
Baumann-components of finite groups of characteristic p, general theory
No full textIn this paper we introduce a new conjugacy class Bau_p(G) of p-subgroups of finite groups G of characteristic p. We then prove some factorization and decomposition theorems related to this conjugacy class. In particular, these results show that the only obstructions for B∈Bau_p(G) being normal in G are the Baumann components of G, a class of subnormal subgroups E with E/Op(E) quasisimple or SL2(p)′ for p≤3
The !-theorem
No full textIn this paper we prove a result that is used in the investigation of finite K_p-groups of local characteristic p. It is part of an attempt to revise a major part of the classification of the finite simple groups. A description of this program can be found in [U.Meierfrankenfeld, B.Stellmacher, G.Stroth, "Finite groups of local characteristic p: an overview", Groups, Combinatorics and Geometry, Durham, 2001 (World Scientific Publishing, River Edge, NJ, 2003) pp. 155-192]
The -Theorem
No full textThe paper under review is part of an ongoing project to give a proof for large parts of the classification of the finite simple groups which is different from the existing one. Moreover, the authors prove some result which is of independent interest.\par They consider the usual amalgam set up, i.e., two groups which are of characteristic -type, share a common Sylow -subgroup but no nontrivial normal subgroup of . Now the special assumptions are (i) , , (ii) There is with , , , or () and is the natural module, . (iii) or and or ; (iv) There is a 2-dimensional singular subspace in such that , .\par Then the authors show that this setup does just occur in very special situations. Either , and or , or or , or and , and and are natural -modules dual to each other.\par This result is similar to the result due to {\it B. Stellmacher} and {\it F. G. Timmesfeld} [Mem. Am. Math. Soc. 649 (1998; Zbl 0911.20024)] but does not follow from that result. This is now used to get a technical result, the -theorem. This under certain assumptions, which are technical, says basically the following. Let be a group with , , of local characteristic , and be a maximal -local containing . As the generic simple group of local characteristic is a group of Lie type over a field of characteristic , the aim is to get a geometry for . In this sense then is a maximal parabolic. Now, the authors consider a minimal parabolic . Under a further technical assumption, they show that there is a unique minimal parabolic containing , which does not normalize or there is one of the exceptions described by the theorem above. Further, they show that the group generated by and is a rank 2 Lie group. So if induces a Lie group this result provides us with a building geometry for .
[Gernot Stroth (Halle)
General offender theory
No full textWe present an offender theory that is symmetric in offender and offended group and also a replacement theorem that does not need that the groups in question are abelian. We then use this theory to define variations of Thompson and Baumann subgroups and prove a general Baumann argument. (C) 2017 Elsevier Inc. All rights reserved
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Eine Lösung des Pushing-up Problems für eine Klasse endlicher Gruppen
No full textMeierfrankenfeld U. Eine Lösung des Pushing-up Problems für eine Klasse endlicher Gruppen. Bielefeld; 1986
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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