• Title/Summary/Keyword: abelian

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RESIDUAL FINITENESS AND ABELIAN SUBGROUP SEPARABILITY OF SOME HIGH DIMENSIONAL GRAPH MANIFOLDS

  • Kim, Raeyong
    • Korean Journal of Mathematics
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    • v.29 no.3
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    • pp.603-612
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    • 2021
  • We generalize 3-manifolds supporting non-positively curved metric to construct manifolds which have the following properties : (1) They are not locally CAT(0). (2) Their fundamental groups are residually finite. (3) They have subgroup separability for some abelian subgroups.

TATE-SHAFAREVICH GROUPS OVER THE COMMUTATIVE DIAGRAM OF 8 ABELIAN VARIETIES

  • Hoseog Yu
    • Honam Mathematical Journal
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    • v.45 no.3
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    • pp.410-417
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    • 2023
  • Suppose that there are 8 abelian varieties defined over a number field K which satisfy a commutative diagram. We show that if we know that three out of four short exact sequences satisfy the rate formula of Tate-Shafarevich groups, then the unknown short exact sequence satisfies the rate formula of Tate-Shafarevich groups, too.

TATE-SHAFAREVICH GROUPS AND SCHANUEL'S LEMMA

  • Yu, Hoseog
    • Honam Mathematical Journal
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    • v.39 no.2
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    • pp.137-141
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    • 2017
  • Let A be an abelian variety defined over a number field K and let L be a finite Galois extension of K. Let III(A/K) and III(A/L) denote, respectively, the Tate-Shafarevich groups of A over K and over L. Let $Res_{L/K}(A)$ be the restriction of scalars of A from L to K and let B be an abelian subvariety of $Res_{L/K}(A)$ defined over K. Assuming that III(A/L) is finite, we compute [III(B/K)][III(C/K)]/[III(A/L)], where [X] is the order of a finite abelian group X and the abelian variety C is defined by the exact sequence defined over K $0{\longrightarrow}B{\longrightarrow}Res_{L/K}(A){\longrightarrow}C{\longrightarrow}0$.

A Survey of Public-Key Cryptography over Non-Abelian Groups

  • Lanel, G.H.J.;Jinasena, T.M.K.K.;Welihinda, B.A.K.
    • International Journal of Computer Science & Network Security
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    • v.21 no.4
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    • pp.289-300
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    • 2021
  • Non-abelian group based Cryptography is a field which has become a latest trend in research due to increasing vulnerabilities associated with the abelian group based cryptosystems which are in use at present and the interesting algebraic properties associated that can be thought to provide higher security. When developing cryptographic primitives based on non-abelian groups, the researchers have tried to extend the similar layouts associated with the traditional underlying mathematical problems and assumptions by almost mimicking their operations which is fascinating even to observe. This survey contributes in highlighting the different analogous extensions of traditional assumptions presented by various authors and a set of open problems. Further, suggestions to apply the Hamiltonian Cycle/Path Problem in a similar direction is presented.

RINGS IN WHICH EVERY SEMICENTRAL IDEMPOTENT IS CENTRAL

  • Muhammad Saad
    • Korean Journal of Mathematics
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    • v.31 no.4
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    • pp.405-417
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    • 2023
  • The RIP of rings was introduced by Kwak and Lee as a generalization of the one-sided idempotent-reflexivity property. In this study, we focus on rings in which all one-sided semicentral idempotents are central, and we refer to them as quasi-Abelian rings, extending the concept introduced by RIP. We establish that quasi-Abelianity extends to various types of rings, including polynomial rings, power series rings, Laurent series rings, matrices, and certain subrings of triangular matrix rings. Furthermore, we provide comprehensive proofs for several results that hold for RIP and are also satisfied by the quasi-Abelian property. Additionally, we investigate the structural properties of minimal non-Abelian quasi-Abelian rings.

SOME REDUCED FREE PRODUCTS OF ABELIAN C*

  • Heo, Jae-Seong;Kim, Jeong-Hee
    • Bulletin of the Korean Mathematical Society
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    • v.47 no.5
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    • pp.997-1000
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    • 2010
  • We prove that the reduced free product of $k\;{\times}\;k$ matrix algebras over abelian $C^*$-algebras is not the minimal tensor product of reduced free products of $k\;{\times}\;k$ matrix algebras over abelian $C^*$-algebras. It is shown that the reduced group $C^*$-algebra associated with a group having the property T of Kazhdan is not isomorphic to a reduced free product of abelian $C^*$-algebras or the minimal tensor product of such reduced free products. The infinite tensor product of reduced free products of abelian $C^*$-algebras is not isomorphic to the tensor product of a nuclear $C^*$-algebra and a reduced free product of abelian $C^*$-algebra. We discuss the freeness of free product $II_1$-factors and solidity of free product $II_1$-factors weaker than that of Ozawa. We show that the freeness in a free product is related to the existence of Cartan subalgebras in free product $II_1$-factors. Finally, we give a free product factor which is not solid in the weak sense.

ON THE TATE-SHAFAREVICH GROUPS OVER DEGREE 3 NON-GALOIS EXTENSIONS

  • Yu, Hoseog
    • Honam Mathematical Journal
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    • v.38 no.1
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    • pp.85-93
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    • 2016
  • Let A be an abelian variety defined over a number field K and let L be a degree 3 non-Galois extension of K. Let III(A/K) and III(A/L) denote, respectively, the Tate-Shafarevich groups of A over K and over L. Assuming that III(A/L) is finite, we compute [III(A/K)][III($A_{\varphi}/K$)]/[III(A/L)], where [X] is the order of a finite abelian group X.

ON ALMOST ω1-pω+n-PROJECTIVE ABELIAN p-GROUPS

  • Danchev, Peter V.
    • Korean Journal of Mathematics
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    • v.22 no.3
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    • pp.501-516
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    • 2014
  • We define the class of almost ${\omega}_1-p^{\omega+n}$-projective abelian p-primary groups and investigate their basic properties. The established results extend classical achievements due to Hill (Comment. Math. Univ. Carol., 1995), Hill-Ullery (Czech. Math. J., 1996) and Keef (J. Alg. Numb. Th. Acad., 2010).