Vol 218, No 1 (2016)

A nonlocal boundary-value problem for the differential equation with weak nonlinearity and with differential operator B = (B₁, …, B_p), where \( {B}_j\equiv {z}_j\frac{\partial }{\partial {z}_j}\;\mathrm{and}\;j=1,\dots, p \) is considered. By using the Nash–Moser iterative scheme, the solvability conditions for the present problem in the Hilbert H¨ormander spaces of functions of many complex variables forming a refined Sobolev scale of spaces is established.

The solution of the stochastic equation X(t) = x₀ + b∫₀^tsign(X(s))|X(s)|^γds + w(t); where w(t) is the Wiener process, the constant b ≠ 0, and γ ∈ (0; 1]; is considered. The local principle of large deviations for the sequence of processes \( {X}_n(t)=\frac{X(nt)}{n^{\alpha }},\alpha >1/2 \), is proved. The form of the rate function is found.

The paper is devoted to the development of the theory of lower Q-homeomorphisms relative to a p-modulus in ℝⁿ, n ≥ 2. For these classes of mappings, a number of theorems on the local behavior are established, and, in particular, an analog of the famous Gehring theorem on a local Lipschitz property is proved, various theorems on estimates of distortion of the Euclidean distance are given, an estimate of the ball image measure is established, and, as a consequence, an analog of the Ikoma–Schwartz lemma is proved.

The classes of right and left γ-generating matrices were introduced by D. Z. Arov in the 1980s. These matrices play an important role in the description of solutions of the indeterminate Nehari problem. In the present paper, the classes of the so-called generalized right and left γ-generating matrices, being resolvent matrices of the Nehari–Takagi problem, are introduced. For matrices of these classes, some factorization theorems are proved, and the connection between the class of generalized γ-generating matrices and the class of generalized j_pq-inner matrix valued functions is found. Subclasses of singular, regular, and strongly regular generalized -generating matrices are introduced and studied.