Vdovin, E. P. Revin, D. O.
Published in
Siberian Mathematical Journal

We prove that the Hall subgroups of finite simple groups are pronormal. Thus we obtain an affirmative answer to Problem 17.45(a) of the Kourovka Notebook.

Khisamiev, A. N.
Published in
Siberian Mathematical Journal

We obtain a sufficient condition for the absence of any universal Σ-function in an admissible set (a hereditarily finite admissible set). We construct a tree T of height 4 such that no universal Σ-function exists in the hereditarily finite admissible set ℍ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} ...

Abanina, D. A.
Published in
Siberian Mathematical Journal

We establish a solvability criterion for convolution equations in the Beurling classes of ultradifferentiable functions of mean type on an interval. Under study is also the question of degeneration of convolution equations into infinite-order equations with constant coefficients.

Iskenderov, B. A. Mamedov, Dzh. Yu.
Published in
Siberian Mathematical Journal

We obtain large time asymptotic expansions of the solution to the Cauchy problem and the first and second boundary value problems for the Sobolev equation in the quadrant.

Sabitov, K. B. Martem’yanova, N. V.
Published in
Siberian Mathematical Journal

We examine a mixed type equation with the Lavrent’ev-Bitsadze operator and an unknown right-hand side in a rectangle and study a nonlocal boundary value problem in which the values of the stream function on the lateral sides of the rectangle are equal. The solution is given as a sum of a biorthogonal series. The uniqueness criterion and stability o...

Plotnikova, A. N.
Published in
Siberian Mathematical Journal

We prove a theorem on the short-time existence of a flow quadratic in the Ricci tensor for Riemannian metrics on compact manifolds under certain conditions. Also, we construct formulas of the deformation of the Ricci curvature tensor for this flow.

Sevost’yanov, E. A.
Published in
Siberian Mathematical Journal

We study space mappings more general than the mappings with bounded distortion in the sense of Reshetnyak. We consider questions related to the local behavior of mappings differentiable almost everywhere, possessing Properties N, N−1, ACP, and ACP−1, and such that quasiconformality coefficient satisfies a certain restriction on growth. We show that...

Veretennikov, B. M.
Published in
Siberian Mathematical Journal

By an Alperin group we mean a group in which the commutant of each 2-generated subgroup is cyclic. Alperin proved that if p is an odd prime then all finite p-groups with this property are metabelian. The today’s actual problem is the construction of examples of nonmetabelian finite Alperin 2-groups. Note that the author had given some examples of f...

Tersenov, Ar. S.
Published in
Siberian Mathematical Journal

Under consideration is the Dirichlet problem for singular anisotropic elliptic equations with a nonlinear source. Some new a priori estimates are obtained, implying that the solvability of the Dirichlet problem in the class of bounded solutions essentially depends on the dimension of the domain of the problem.

Staroletov, A. M.
Published in
Siberian Mathematical Journal

The spectrum of a finite group is the set of its element orders. Two groups are isospectral whenever they have the same spectra. We consider the classes of finite groups isospectral to the simple symplectic and orthogonal groups B3(q), C3(q), and D4(q). We prove that in the case of even characteristic and q > 2 these groups can be reconstructed fro...