Let G be an arbitrary FC-group, let R be its locally soluble radical, and let L/R = L(G/R). We prove that, for N ⊲ G, G/N is residually finite if R ⊆ N ⊆ L.
The convergence rates of the regularized solution as well as its Galerkin approximations for nonlinear monotone ill-posed problems in a Banach space are established on the basis of the choice of a regularization parameter ...
The model Fröhlich–Peierls Hamiltonian for electrons interacting with phonons only in some infinite discrete modes is considered. It is shown that, in the equilibrium case, this model is thermodynamically equivalent to the ...
We prove that a conditional expectation on a Kac algebra, under certain conditions, decomposes into a composition of two conditional expectations of a special type and gives rise to a compact quantum hypergroup connected ...
We consider initial-value problems for infinite systems of first-order partial functional differential equations. The unknown function is the functional argument in equations and the partial derivations appear in the ...
Отримано критерій існування тa єдиності розв'язків лінійного різницевого рівняння з необмеженим операторним коефіцієнтом, що належать простору lᵖ(B) послідовностей елементів банахового простору B.
We consider the model and approximating Hamiltonians directly in the case of infinite volume. We show that each of these Hamiltonians has two branches of the spectrum and two systems of eigenvectors, which represent ...
The convergence of polymer cluster expansions for correlation functions of general Gibbs oscillator-type systems and related nonequilibrium systems of Brownian oscillators is established. The initial states for the latter ...
Nguyen Minh Man; Nguyen The Hoan(Український математичний журнал, 2003)
We present sufficient conditions for the linear asymptotic equilibrium of linear differential equations in Hilbert and Banach spaces. The results obtained are applied to studying the asymptotic equivalence of two linear ...
We consider the first initial boundary-value problem for a strongly parabolic system on an infinite cylinder with nonsmooth boundary. We prove some results on the existence, uniqueness, and asymptotic behavior of solutions ...
The difference sequence spaces ℓ∞(△), c(△), and c₀(△) were studied by Kızmaz. The main purpose of the present paper is to introduce the space bv p consisting of all sequences whose differences are in the space ℓp , and to ...
We study the problem of the existence of multiple periodic solutions of the Hamiltonian system
Jx˙+u∇G(t,u(x))=e(t),
where u is a linear mapping, G is a C¹-function, and e is a continuous function.
We derive an explicit formula for the Jacobi field that is acting in an extended Fock space and corresponds to an ( R -valued) Lévy process on a Riemannian manifold. The support of the measure of jumps in the Lévy–Khintchine ...
We analyze the geometric structure of the Lyapunov–Schmidt approach to studying critical manifolds of weakly perturbed Lagrangian and Hamiltonian systems.
We study the problem of the complete integrability of nonlinear oscillatory dynamical systems connected, in particular, both with the Cartan decomposition of a Lie algebra G=K⊕P, where K is the Lie algebra of a fixed ...
For the equation L₀x(t) + L₁x⁽¹⁾(t) + ... + Lnx⁽ⁿ⁾(t) = 0, where Lk, k = 0, 1, ... , n, are operators acting in a Banach space, we formulate conditions under which a solution x(t) that satisfies some nonlocal homogeneous ...
Побудовано спеціальний агрегаційно-ітеративний алгоритм — двопараметричиий метод ітеративного агрегування для диференціального рівняння з двоточковими крайовими умовами. Встановлено умови збіжності методу. Наведено частинні ...
У комутативних, асоціативних третього рангу алгебрах із головною одиницею над комплексним полем виділено такі базиси, що гіперкомплексні моногенні функції, побудовані в цих базисах, мають компоненти, що задовольняють ...