高级检索

 作者：E. Herscovich 来源：[J].Ukrainian Mathematical Journal(IF 0.154), 2020, Vol.71 (11), pp.1294-1302Springer 摘要：The aim of this short note is to complete some aspects of a theorem proved by S. Merkulov in [ Int. Math. Res. Not. IMRN , 3 , 153–167 (1999)] (Theorem 3.4), as well as to provide a complete proof of the dual result for dg coalgebras.
 作者：B. I. Hladysh , O. O. Prishlyak 来源：[J].Ukrainian Mathematical Journal(IF 0.154), 2020, Vol.71 (4), pp.1173-1185Springer 摘要：We consider simple functions with nondegenerate singularities on smooth compact oriented surfaces with boundary. The relationship between the optimality and polarity of Morse functions, m -functions and mm -functions on smooth compact oriented connected surfaces is described...
 作者：F. G. Abdullayev , D. M. Bushev , M. Imash kyzy ... 来源：[J].Ukrainian Mathematical Journal(IF 0.154), 2020, Vol.71 (6), pp.1153-1172Springer 摘要：We determine the subspaces of solutions of the systems of Laplace and heat-conduction differential equations isometric to the corresponding spaces of real functions defined on the set of real numbers.
 作者：A. Yu. Khamrayev 来源：[J].Ukrainian Mathematical Journal(IF 0.154), 2020, Vol.71 (6), pp.1273-1281Springer 摘要：We find all fixed and periodic points for a quasistrictly non-Volterra quadratic stochastic operator on a two-dimensional simplex. The description of the limit set of trajectories is presented for this operator.
 作者：S. S. Zhumatov 来源：[J].Ukrainian Mathematical Journal(IF 0.154), 2020, Vol.71 (4), pp.1202-1213Springer 摘要：We study the absolute stability of the program manifold of basic control systems with variable coefficients and stationary nonlinearities. The conditions of stability of basic systems are investigated in a neighborhood of a given program manifold. The nonlinearities satisfy the c...
 作者：A. I. Noarov 来源：[J].Ukrainian Mathematical Journal(IF 0.154), 2020, Vol.71 (3), pp.1303-1311Springer 摘要：We prove inequalities connecting a flow through the ( n− 1)-dimensional surface S of a smooth solenoidal vector field with its L p ( U )-norm ( U is an n -dimensional domain that contains S ). On the basis of these inequalities, we propose a correct definition of...
 作者：L. K. Ha 来源：[J].Ukrainian Mathematical Journal(IF 0.154), 2020, Vol.71 (8), pp.1234-1256Springer 摘要：We study the initial-value problems for the heat equations associated with the operator □ b on compact CR manifolds of finite type. The critical component of our analysis is the condition called D ϵ( q ) and introduced by K. D. Koenig [ Amer. J. Math. ...
 作者：B. de Malafosse 来源：[J].Ukrainian Mathematical Journal(IF 0.154), 2020, Vol.71 (17), pp.1186-1201Springer 摘要：Given any sequence a = ( a n ) n ≥1 of positive real numbers and any set E of complex sequences, we write E a for the set of all sequences y = ( y n ) n ≥1 such that y/a = ( y n /a n ) n...
 作者：S. Kharibegashvili , B. Midodashvili 来源：[J].Ukrainian Mathematical Journal(IF 0.154), 2020, Vol.71 (3), pp.1282-1293Springer 摘要：We consider a boundary-value problem for a semilinear hyperbolic equation with iterated multidimensional wave operator in the principal part. The theorems on existence, uniqueness, and nonexistence of solutions of this problem are established.
 作者：A. K. Kushpel 来源：[J].Ukrainian Mathematical Journal(IF 0.154), 2020, Vol.71 (2), pp.1224-1233Springer 摘要：We present the solution of a classical problem of approximation theory about the sharp asymptotics of Lebesgue constants or the norms of Fourier–Laplace projections on the real sphere S d \documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfon...