О Тригонометрическом (0, 2)-Интерполировании

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On smoothness of <Emphasis Type="Italic">L</Emphasis><Subscript>3,∞</Subscript>-solutions to the Navier–Stokes equations up to boundary

We show that L_3,-solutions to the three-dimensional Navier-Stokes equations near a flat part of the boundary are smooth.Mathematics Subject Classification (1991): 35K, 76D     

Some remarks on the boundary regularity for minima of variational problems with obstacles

We minimize the Dirichlet-integral in a class of vector-valued functions u:^N defined by Dirichlet-boundary conditions and a side-condition of the form u()M with M bounded and open in ^N having smooth boundary M. If the boundary values are sufficiently regular we show that the minimizer can only have interior singularities, i.e. the solution is smooth in a neighborhood of .     

The Laplacian with Wentzell-Robin Boundary Conditions on Spaces of Continuous Functions

We investigate the Laplacian on a smooth bounded open set Rn with Wentzell-Robin boundary condition $\beta u+\frac{\partial u}{\partial \nu} + \Delta u=0$ on the boundary . Under the assumption $\memb$ C() with $\geq$ 0 , we prove that generates a differentiable positive contraction semigroup on $C(\bar{\Omega})$ and study some monotonicity properties and the asymptotic behaviour.     

Construction in a piecewise smooth domain of a function of the class H2 from the value of the conormal derivative

The problem of the construction in a bounded domain ^m with a Lipschitz boundary of a function H²(), for which the conormal derivative on coincides with the normal component of a given vector field u H¹(,C ³), is discussed. The solution of this problem is given for piecewise smooth boundaries in the case m=3.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 163, pp. 17–28, 1987.     

О граничном поведени и неограниченных супергармонических функций

In this paper it is proved that a function, superharmonic on a domain inR ⁿ⁺¹ with Lipschitz boundary, cannot have nontangential limit equal to + on a set of positiven-dimensional measure on the boundary. As a corollary, a generalization of the uniqueness theorem of Lusin-Privalov on the nontangential limits of functions, analytic on a domain in the complex plane, is obtained for the case of functions, analytic on a domain in C ⁿ (n>1) with Lipschitz boundary. Formulation of a generalization of the main theorem is also given for the case of the solutions of uniformly elliptic equations with infinitely smooth coefficients.

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Fine Analysis of the Quasi-Orderings on the Power Set

We pursue the fine analysis of the quasi-orderings and on the power set of a quasi-ordering (Q,). We set X Y if every xX is majorized in by some yY, and X Y if every yY is minorized in by some xX. We show that both these quasi-orderings are -wqo if and only if the original quasi-ordering is ( )-wqo. For this holds also restricted to finite subsets, thus providing an example of a finitary operation on quasi-orderings which does not preserve wqo but preserves bqo.     

On shifts of sequences

X ₂ ={x _k } _k=2 X={x _k } _k=1 . , , ( , ) . , , X— , , X ₂ H, , , , , X ₂ H.     

The possibility of integral formulas in R n

We consider the integral We solve the problem of determination of necessary and sufficient conditions in order that (u) be independent of the values of u(x) inside a bounded domain . These conditions are written in the form of a set of differential equations for the functions f(x,u,¯p,T^ij) on the set m{x; u+¯p+ T^ij<}. For such functions (u) is represented in the form of a boundary integral.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 52, pp. 35–51, 1975.     

On the approximation to solutions of operator equations by the least squares method

We consider the equation Au = f, where A is a linear operator with compact inverse A ^–1 in a separable Hilbert space . For the approximate solution u _n of this equation by the least squares method in a coordinate system {e _k } _k that is an orthonormal basis of eigenvectors of a self-adjoint operator B similar to A ( (B) = (A)), we give a priori estimates for the asymptotic behavior of the expressions r _n = u _n – u and R _n = Au _n – f as n . A relationship between the order of smallness of these expressions and the degree of smoothness of u with respect to the operator B is established.__________Translated from Funktsional nyi Analiz i Ego Prilozheniya, Vol. 39, No. 1, pp. 85–90, 2005Original Russian Text Copyright © by M. L. GorbachukSupported by CRDF and Ukrainian Government Joint Grant UM1-2567-OD03.Translated by V. M. Volosov