A convolution metric in the space of measures and ε-isometries in Lp

For >0, 2,4,6,... on the set of those Borel measures on , such that x^pd(x)<, one introduces a metric, characterizing the nearness of the convolutions x^p* and x^p*. From the convergence of a sequence of probability measures in this metric there follows its convergence in the Kantorovich-Rubinshtein metric. From here one derives theorems on the approximation of -isometries: if H is a finite-dimensional subspace in L_p, then there exists a continuous function _H(), such that for any linear -isometric operator THL_p there exists a linear isometry UH L_p, such that T–U<_H().Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 157, pp. 151–156, 1987.     

A Remark on the Generalized Roper-Suffridge Extension Operator for Spirallike Mappings of Type β and Order α

Suppose f is a spirallike function of type β and order α on the unit disk D.let Ωn,p1,p2,…,pn={z=(z1,z2,…,zn)'∈Cn:nΣj=1|zj|pj<1},where 1≤p1≤2,pj≥1,j=2,…,n,are real numbers. In this paper,we will prove that Фn,β2,у2…βn,уn(f)(z)=(f(z1),(f(z1)z1)β2(f'(z1))у2z2,…,(f(z1)z1)βn(f'(z1))уnzn)' Preserves spirallikeness of type β and order α on Ωn,p1,p2,…pn.     

Generalized Fourier–Feynman transforms and generalized convolution products on Wiener space

In this paper we define a more general convolution product of functionals on Wiener space and develop the fundamental relationships between the generalized Fourier–Feynman transform and the convolution product.     

Schrödinger operators with singular potentials from the space of multiplicators

We study Schrödinger operatorsT+Q, whereT=?Δ is the Laplace operator andQ is the multiplication operator by a generalized function (distribution). We also consider generalizations for the case of the polyharmonic operatorT = (-δ) ⁿ      

Generalized Smoothness and Approximation of Periodic Functions in the Spaces Lp, 1 < p < +∞

Mathematical Notes - Norms of images of operators of multiplier type with an arbitrary generator are estimated by using best approximations of periodic functions of one variable by trigonometric...     

A Remark on the Generalized Roper-Suffridge Extension Operator for Almost Stalike Mappings of Order α

Suppose f is an almost starlike function of orderαon the unit disk D.In this paper,we will prove thatΦ_(n,β_2,γ_2,…,β_n,γ_n)(f)(z)=(f(z_1),((f(z_1)/z_1))~β_2(f′(z_1))~(γ_2)z_2,…, ((f(z_1)/z_1))~(β_n)(f′(z_1))~(γ_n)z_n)′preserves almost starlikeness of orderαonΩ_(n,p_1,p_2,…,p_n)={z= (z_1,z_2,…,z_n)′∈C~n:(sum from j=1 to n)|z_j|~(p_j)<1},where 0相似文献   

Boundary Behavior of α-Harmonic Functions on the Complement of the Sphere and Hyperplane

We study α-harmonic functions on the complement of the sphere and on the complement of the hyperplane in Euclidean spaces of dimension bigger than one, for α?∈?(1,2). We describe the corresponding Hardy spaces and prove the Fatou theorem for α-harmonic functions. We also give explicit formulas for the Martin kernel of the complement of the sphere and for the harmonic measure, Green function and Martin kernel of the complement of the hyperplane for the symmetric α-stable Lévy processes. Some extensions for the relativistic α-stable processes are discussed.     

A Note on the Toughness of Generalized Petersen Graphs

We show that,for each integer n≥5,the toughness of a generalized Petersengraph with 2n vertices is less than or equal to 4/3,and 4/3 is the best upper bound.     

On the riesz charge of the lower envelope of δ-subharmonic functions

By potential theoretic methods involving the Cartan fine topology a recent result by two of the authors is extended as follows: The Riesz charge of the lower envelope of a family of 3 or more -subharmonic functions (no longer supposed continuous) in the plane equals the infimum of the charges of the lower envelopes of all pairs of functions from the family. As a key to this it is shown in two different ways that the (fine) harmonic measures of any 3 pairwise disjoint finely open planar sets have Borel supports with empty intersection. One proof of this uses the Jordan curve theorem and the fact that the set of inaccessible points of the fine boundary of a fine domain is Borel and has zero harmonic measure; the other involves Carleman-Tsuji type estimates together with a fine topology version of a recent result of P. Jones and T. Wolff on harmonic measure and Hausdorff dimension.     

ζ-determinant and the Quillen determinant on the Grassmannian of elliptic self-adjoint boundary conditions

We announce a proof of the equality of the ζ-determinant of a Dirac operator over an odd-dimensional manifold with boundary with the Quillen determinant section computed in a canonical trivialization over the Grassmannian of elliptic self-adjoint boundary conditions.     

Cones in the space Lp (1 ≤ p ≤ ∞) and minimax problems of mathematical statistics

The structure of cones in the spaces L_p(l p ) and their application to minimax problems of statistical assumptions are considered.Translated from Staticheskie Metody, pp. 28–30, 1978.