Перегляд за автором "Semko, N.N."

Сортувати за: Порядок: Результатів:

  • A generalization of the malnormal subgroups 
    Kurdachenko, L.A.; Semko, N.N.; Subbotin, I.Ya. (Доповіді НАН України, 2019)
    A subgroup H of a group G is called malonormal in G, if H ⌒ H^x = <1> for every element x ∉ NG(H). These subgroups are generalizations of malnormal subgroups. Every malnormal subgroup is malonormal, and every selfnormal ...
  • Groups with small cocentralizers 
    Javier Otal; Semko, N.N. (Algebra and Discrete Mathematics, 2009)
    Let G be a group. If S⊆G is a G-invariant subset of G, the factor-group G/CG(S) is called the cocentralizer of S in G. In this survey-paper we review some results dealing with the influence of several cocentralizers on the ...
  • Linear groups saturated by subgroups of finite central dimension 
    Semko, N.N.; Skaskiv, L.V.; Yarovaya, O.A. (Algebra and Discrete Mathematics, 2020)
    Let F be a field, A be a vector space over F and G be a subgroup of GL(F,A). We say that G has a dense family of subgroups, having finite central dimension, if for every pair of subgroups H, K of G such that H ≤ K and H ...
  • Linear groups saturated by subgroups of finite central dimension 
    Semko, N.N.; Skaskiv, L.V.; Yarovaya, O.A. (Доповіді НАН України, 2019)
    Let F be a field, A be a vector space over F, and G be a subgroup of GL(F, A). We say that G has a dense family of subgroups having finite central dimension, if, for every pair of subgroups H, K of G such that H ≤ K and ...
  • On analogs of some group-theoretic concepts and results for Leibniz algebras 
    Kurdachenko, L.A.; Subbotin, I.Ya.; Semko, N.N. (Доповіді НАН України, 2018)
    An algebra L over a field F is said to be a Leibniz algebra (more precisely a left Leibniz algebra) if it satisfies the Leibniz identity: [[a, b], c] = [a, [b, c]] – [b, [a, c]] for all a, b, c ∈ L. Leibniz algebras are ...
  • On groups whose subgroups of infinite special rank are transitively normal 
    Semko, N.N.; Velychko, T.V. (Algebra and Discrete Mathematics, 2017)
    This paper sheds a light on periodic soluble groups whose subgroups of infinite special rank are transitively normal.
  • On some generalization of metahamiltonian groups 
    Semko, N.N.; Yarovaya, O.A. (Algebra and Discrete Mathematics, 2009)
    Locally step groups at which all subgroups are or normal, or have Chernikov’s derived subgroup are studied.
  • On some topics in the theory of infinite dimensional linear groups 
    Dixon, M.R.; Kurdachenko, L.A.; Semko, N.N.; Subbotin, I.Ya. (Algebra and Discrete Mathematics, 2020)
    In this paper we present a synopsis of some recent results concerned with infinite dimensional liner groups, including generalizations of irreducibility, the central dimension of a linear group, groups with finite dimensional ...
  • On the anticommutativity in Leibniz algebras 
    Kurdachenko, L.A.; Semko, N.N.; Subbotin, I.Ya. (Algebra and Discrete Mathematics, 2018)
    Lie algebras are exactly the anticommutative Leibniz algebras. In this article, we conduct a brief analysis of the approach to Leibniz algebras which based on the concept of the anti-center (Lie-center) and antinilpotency ...
  • On the role played by anticommutativity in Leibniz algebras 
    Kurdachenko, L.A.; Semko, N.N.; Subbotin, I.Ya. (Доповіді НАН України, 2019)
    Lie algebras are exactly the anticommutative Leibniz algebras. We conduct a brief analysis of the approach to Leibniz algebras which is based on the concept of anticenter (Lie-center) and antinilpotency (Lie nilpotentency).
  • On the structure of Leibniz algebras whose subalgebras are ideals or core-free 
    Chupordia, V.A.; Kurdachenko, L.A.; Semko, N.N. (Algebra and Discrete Mathematics, 2020)
    An algebra L over a field F is said to be a Leibniz algebra (more precisely, a left Leibniz algebra) if it satisfies the Leibniz identity: [[a, b], c] = [a, [b, c]]−[b, [a, c]] for all a, b, c ∊ L. Leibniz algebras are ...
  • On the structure of Leidniz algebras, whose subalgebras are ideals or core-free 
    Chupordia, V.A.; Kurdachenko, L.A.; Semko, N.N. (Доповіді НАН України, 2020)
    An algebra L over a field F is said to be a Leibniz algebra (more precisely, a left Leibniz algebra), if it satisfies the Leibniz identity: [[a, b], c] = [a, [b, c]] — [b, [a, c]] for all a, b, c ∈ L. Leibniz algebras are ...
  • On the structure of some groups having finite contranormal subgroups 
    Kurdachenko, L.A.; Semko, N.N. (Algebra and Discrete Mathematics, 2021)
    Following J.S. Rose, a subgroup H of the group G is said to be contranormal in G, if G = Hᴳ. In a certain sense, contranormal subgroups are antipodes to subnormal subgroups. We study the structure of Abelian-by-nilpotent ...
  • S. N. Chernikov and the development of infinite group theory 
    Dixon, M.R.; Kirichenko, V.V.; Kurdachenko, L.A.; Otal, J.; Semko, N.N.; Shemetkov, L.A.; Subbotin, I.Ya. (Algebra and Discrete Mathematics, 2012)
    In this survey, the authors want to show the development and continuation of some studies, in which S.N.Chernikov stood as the main originator and to demonstrate clearly the extent of influence exerted by the ideas and ...
  • The groups whose cyclic subgroups are either ascendant or almost self-normalizing 
    Kurdachenko, L.A.; Pypka, A.A.; Semko, N.N. (Algebra and Discrete Mathematics, 2016)
    The main result of this paper shows a description of locally finite groups, whose cyclic subgroups are either almost self-normalizing or ascendant. Also, we obtained some natural corollaries of the above situation.
  • The structure of infinite dimensional linear groups satisfying certain finiteness conditions 
    Jose M. Munoz-Escolano; Javier Otal; Semko, N.N. (Algebra and Discrete Mathematics, 2009)
    We review some recent results on the structure of infinite dimensional linear groups satisfying some finiteness conditions on certain families of subgroups. This direction of research is due to Leonid A. Kurdachenko, who ...