Anti-invariant Riemannian submersions from almost Hermitian manifoldsCentral European Journal of Mathematics - Tập 8 - Trang 437-447 - 2010
Bayram Ṣahin
We introduce anti-invariant Riemannian submersions from almost Hermitian manifolds onto Riemannian manifolds. We give an example, investigate the geometry of foliations which are arisen from the definition of a Riemannian submersion and check the harmonicity of such submersions. We also find necessary and sufficient conditions for a Langrangian Riemannian submersion, a special anti-invariant Riema...... hiện toàn bộ
On the asymptotic form of convex hulls of Gaussian random fieldsCentral European Journal of Mathematics - Tập 12 - Trang 711-720 - 2014
Youri Davydov, Vygantas Paulauskas
We consider a centered Gaussian random field X = {X
t : t ∈ T} with values in a Banach space
$$\mathbb{B}$$
defined on a parametric set T equal to ℝ
m
or ℤ
m
. It is supposed that the distribution
...... hiện toàn bộ
Gonality for stable curves and their maps with a smooth curve as their targetCentral European Journal of Mathematics - - 2008
Edoardo Ballico
Here we study the deformation theory of some maps f: X → ℙ
r
, r = 1, 2, where X is a nodal curve and f|T is not constant for every irreducible component T of X. For r = 1 we show that the “stratification by gonality” for any subset of
with fixed topological type behaves like the stratifi...... hiện toàn bộ
On the existence of solutions for nonlinear impulsive periodic viable problemsCentral European Journal of Mathematics - Tập 2 - Trang 573-583 - 2004
Tiziana Cardinali, Raffaella Servadei
In this paper we prove the existence of periodic solutions for nonlinear impulsive viable problems monitored by differential inclusions of the type x′(t)∈F(t,x(t))+G(t,x(t)). Our existence theorems extend, in a broad sense, some propositions proved in [10] and improve a result due to Hristova-Bainov in [13].
An adaptive finite element method for Fredholm integral equations of the first kind and its verification on experimental dataCentral European Journal of Mathematics - Tập 11 - Trang 1489-1509 - 2013
Nikolay Koshev, Larisa Beilina
We propose an adaptive finite element method for the solution of a linear Fredholm integral equation of the first kind. We derive a posteriori error estimates in the functional to be minimized and in the regularized solution to this functional, and formulate corresponding adaptive algorithms. To do this we specify nonlinear results obtained earlier for the case of a linear bounded operator. Numeri...... hiện toàn bộ
Maximal subgroups and PST-groupsCentral European Journal of Mathematics - Tập 11 - Trang 1078-1082 - 2013
Adolfo Ballester-Bolinches, James C. Beidleman, Ramón Esteban-Romero, Vicent Pérez-Calabuig
A subgroup H of a group G is said to permute with a subgroup K of G if HK is a subgroup of G. H is said to be permutable (resp. S-permutable) if it permutes with all the subgroups (resp. Sylow subgroups) of G. Finite groups in which permutability (resp. S-permutability) is a transitive relation are called PT-groups (resp. PST-groups). PT-, PST- and T-groups, or groups in which normality is transit...... hiện toàn bộ
Norm conditions for real-algebra isomorphisms between uniform algebrasCentral European Journal of Mathematics - Tập 8 - Trang 135-147 - 2010
Rumi Shindo
Let A and B be uniform algebras. Suppose that α ≠ 0 and A
1 ⊂ A. Let ρ, τ: A
1 → A and S, T: A
1 → B be mappings. Suppose that ρ(A
1), τ(A
1) and S(A
1), T(A
1) are closed under multiplications and contain expA and expB, respectivel...... hiện toàn bộ
On variational impulsive boundary value problemsCentral European Journal of Mathematics - Tập 10 - Trang 1969-1980 - 2012
Marek Galewski
Using the variational approach, we investigate the existence of solutions and their dependence on functional parameters for classical solutions to the second order impulsive boundary value Dirichlet problems with L1 right hand side.