# Afrika Matematika

Afrika Matematika > 2011 > 22 > 1 > 5-17

Afrika Matematika > 2011 > 22 > 1 > 79-89

*p*-adic closure of a subgroup of rational points on a commutative algebraic group. More recently, Bellaïche asked the same question for the special case of Abelian varieties. These problems are

*p*-adic analogues of a question raised earlier by Mazur on the density of rational points for the real topology. For a simple Abelian variety over the field of rational...

Afrika Matematika > 2011 > 22 > 1 > 91-104

*G*be an algebraic group over a field

*F*. In this paper, we study profinite equivariant higher algebraic

*K*-theory for the actions of

*G*leading to computations of profinite higher algebraic

*K*-theory of twisted flag varieties. More precisely, let $${_{\gamma}\mathcal{F}}$$ be a twisted flag variety (see 1.2.3),

*B*a finite dimensional separable

*F*-algebra, and

*ℓ*an odd rational prime. When

*F*is...

Afrika Matematika > 2011 > 22 > 1 > 57-64

*A*

_{1}(

*k*) =

*k*[

*x*,

*y*] with the relation

*yx*−

*xy*= 1, be the first Weyl algebra over a field

*k*. It is well known that the group

*G*: =

*Aut*

_{ k }(

*A*

_{1}(

*k*)) of the

*k*-automorphisms of

*A*

_{1}(

*k*) is an amalgamate group with two of its subgroups (see Alev in Commun Algebra 14(8):1365–1378, 1986), so

*G*must have non-trivial normal subgroups. But none of such subgroup is known. When the field

*k*is a finite set, we reveal...

Afrika Matematika > 2011 > 22 > 1 > 65-78

Afrika Matematika > 2011 > 22 > 1 > 19-31

Afrika Matematika > 2011 > 22 > 1 > 33-55

Afrika Matematika > 2011 > 22 > 2 > 115-127

*BE*-algebras are introduced. We state and prove some theorems in fuzzy

*BE*-algebras and level subalgebras. Some characterizations of fuzzy subalgebras of

*BE*-algebras are given. Using fuzzy subalgebras, characterizations of Artinian and Noetherian

*BE*-algebras are also established. Finally the notion of fuzzy topological

*BE*-algebras is introduced. We state and prove the...

Afrika Matematika > 2011 > 22 > 2 > 153-176

*L*

^{1}-spaces are given. We show that space homogeneous linear kinetic equations in

*L*

^{1}spaces and full transport equations $${\Big({\rm with\,advection\, term} v.\frac{\partial}{\partial x}\Big)}$$ in

*L*

^{1}spaces on arbitrary spatial domains share several generation properties. In particular, in the subcritical case, they share the so-called...

Afrika Matematika > 2011 > 22 > 2 > 105-114

Afrika Matematika > 2011 > 22 > 2 > 129-151

*M*. We investigate conditions for an induced Riemann curvature tensor to be an algebraic curvature tensor on

*M*. We introduce the notion of lightlike Osserman submanifolds and an example of 2-degenerate Osserman metric is given. Finally we give some results of symmetry properties on lightlike...

Afrika Matematika > 2011 > 22 > 2 > 177-199

Afrika Matematika > 2012 > 23 > 1 > 11-20

Afrika Matematika > 2012 > 23 > 1 > 109-119

Afrika Matematika > 2012 > 23 > 1 > 85-97

Afrika Matematika > 2012 > 23 > 1 > 1-9

Afrika Matematika > 2012 > 23 > 1 > 21-39

Afrika Matematika > 2012 > 23 > 1 > 121-133

Afrika Matematika > 2012 > 23 > 1 > 41-52