Problem of the motion of two viscous incompressible fluids separated by a closed free interface

A local existence theorem for the problem of unsteady motion of a drop in a viscous incompressible capillary fluid is proved in Sobolev spaces. A linearized problem with known closed interface is also studied in Holder spaces of functions.     

Random Fields with Multifractional Regularity Order on Heterogenous Fractal Domains

In this article, we study the effect of the geometry of a domain with variable local dimension on the regularity/singularity of the restriction of a multifractional random field on such a domain. The theories of reproducing kernel Hilbert spaces (RKHS) and generalized random fields are applied. Fractional Sobolev spaces of variable order are considered as RKHSs of random fields satisfying certain elliptic multifractional pseudodifferential equations. The multifractal spectra of these random fields are trivial due to the regularity assumptions on the variable order of the fractional derivatives. In this article, we introduce a family of RKHSs defined by isomorphic identification with the trace on a compact heterogeneous fractal domain of a fractional Sobolev space of variable order. The local regularity/singularity order of functions in these spaces, which depends on the variable order of the fractional Sobolev space considered and on the local dimension of the domain, is derived. We also study the spectral properties of the family of models introduced in the mean-square sense. In the Gaussian case, random fields with sample paths having multifractional local Hölder exponent are covered in this framework.     

DECOMPOSITION OF BV FUNCTIONS IN CARNOT-CARATHEODORY SPACES

The aim of this paper is to get the decomposition of distributional derivatives of functions with bounded variation in the framework of Carnot-Caratheodory spaces (C-C spaces in brievity) in which the vector fields are of Carnot type. For this purpose the approximate continuity of BV functions is discussed first, then approximate differentials of L1 functions are defined in the case that vector fields are of Carnot type and finally the     

Chains of function spaces over Euclidian spaces and local fields

The Lipschitz class Lip(K, α) on a local field K is defined in [10], and an equivalent relationship between the Ho¨lder type space Cα(K)[9] and Lip(K,α) is given. In this note, we give a “chain of function spaces“ over Euclidian space by defining higher order continuous modulus in R, and point out that there is no need of higher order continuous modulus for describing the chain of function spaces over local fields.     

Fourier Transform Over Local Fields

The Fourier transform in the space of distributions on finite-dimensional vector spaces over local fields is defined, and a strong similarity between the case of archimedian and non-archimedian fields is discussed. Furthermore, the definition of the Fourier transform for the case of “functions” on finite-dimensional vector spaces over 2-dimensional local fields is introduced. Leonardo da Vinci lecture held on June 29, 2005 Received: October 2005     

New Sobolev spaces via generalized Poincaré inequalities on metric measure spaces

In this paper, we introduce some new function spaces of Sobolev type on metric measure spaces. These new function spaces are defined by variants of Poincaré inequalities associated with generalized approximations of the identity, and they generalize the classical Sobolev spaces on Euclidean spaces. We then obtain two characterizations of these new Sobolev spaces including the characterization in terms of a variant of local sharp maximal functions associated with generalized approximations of the identity. For the well-known Hajłasz–Sobolev spaces on metric measure spaces, we also establish some new characterizations related to generalized approximations of the identity. Finally, we clarify the relations between the Sobolev-type spaces introduced in this paper and the Hajłasz–Sobolev spaces on metric measure spaces.     

Singular Integral Operators with Cauchy Kernel in Fractional Spaces

We single out the Besov spaces that embed into the class of continuous functions and enjoy the Fredholm theory of linear singular integral equations with Cauchy kernel. We give basic results of this theory in the class of continuous (rather than Holder continuous) functions in terms of Besov spaces. Alongside elliptic operators we consider violations of ellipticity: the degeneration of the symbol of an operator at finitely many points.     

A note on the structure of spaces of domino tilings

We study spaces of tilings, formed by tilings which are on a geodesic between two fixed tilings of the same domain (the distance is defined using local flips). We prove that each space of tilings is homeomorphic to an interval of tilings of a domain when flips are classically directed by height functions.     

Distributional Dimension of Fraetal Sets in Local Fields

The distributional dimension of fractal sets in R^n has been systematically studied by Triebel by virtue of the theory of function spaces. In this paper, we first discuss some important properties about the B-type spaces and the F-type spaces on local fields, then we give the definition of the distributional dimension dimD in local fields and study the relations between distributional dimension and Hausdorff dimension. Moreover, the analysis expression of the Hausdorff dimension is given. Lastly, we define the Fourier dimension in local fields, and obtain the relations among all the three dimensions. Keywords local field, B-type space, F-type space, distributional dimension, Hausdorff dimension Fourier dimension     

Paley Type Inequalities for Orthogonal Series with Vector-Valued Coefficients

We investigate the extension to Banach-space-valued functions of the classical inequalities due to Paley for the Fourier coefficients with respect to a general orthonormal system Φ. This leads us to introduce the notions of Paley Φ-type and Φ-cotype for a Banach space and some related concepts. We study the relations between these notions of type and cotype and those previously defined. We also analyze how the interpolation spaces inherit these characteristics from the original spaces, and use them to obtain sharp coefficient estimates for functions taking values in Lorentz spaces.     

Multidirectional Mean Value Inequalities in Quasidifferential Calculus

In the current paper, a Clarke–Ledyaev type mean value inequality is proved for semicontinuous functions defined in a Banach space that are quasidifferentiable in the sense of Demyanov–Rubinov. A stronger variant valid under compactness assumption in separable spaces and extensions for functions with semicontinuous Dini derivatives in locally uniformly convex Banach spaces and with merely bounded Dini derivatives are then established. Subsequently, applications of these mean value inequalities to solvability of nonsmooth parametric equations and to the estimation of local and global Hoffman error bound for inequalities are investigated via a decrease principle.     

DECOMPOSITION OF BV FUNCTIONS IN CARNOT-CARATHÉODORY SPACES

The aim of this paper is to get the decomposition of distributional derivatives of functions with bounded variation in the framework of Carnot-Carathéodory spaces (C-C spaces in brievity) in which the vector fields are of Carnot type. For this purpose the approximate continuity of BV functions is discussed first, then approximate differentials of L¹ functions are defined in the case that vector fields are of Carnot type and finally the decomposition Xu = ∇u · Lⁿ + X^sи is proved, where и ∈ BVx(Ω) and ∇u denotes the approximate differential of u.     

Smoothness spaces of higher order on lower dimensional subsets of the Euclidean space

We study Sobolev type spaces defined in terms of sharp maximal functions on Ahlfors regular subsets of and the relation between these spaces and traces of classical Sobolev spaces.     

一阶HÖlder条件下带参数的修正型Euler-Halley迭代族的局部收敛性

1引言设X和Y为实或复Banach空间,Ω■X是开凸子集,F:Ω■X→Y是一阶连续可微的非线性算子.非线性算子方程F(x)=0 (1.1) 的求解及收敛域问题是现代科学计算理论的基本问题.解方程(1.1)的最著名的迭代方法是Newton法,在适当的条件下,它是二阶收敛的,此即著名的Kantorovich定理.关于Newton法收敛球半径的估计由Traub和王兴华分别给出,见[2]和[3],而收敛性研究的进一步发展可参看[4,5,6]及综述文章[7].     

实值函数与某些覆盖性质

In the paper [properties defined with semi-continuous functions and some related spaces',Houston J.Math.,2015,41(3):1097–1106] properties(U L)~(wl)_m,(U L)~K_m and(U L)_m were defined and it was shown that spaces having these properties coincide with countably paracompact spaces,countably mesocompact spaces and countably metacompact spaces,respectively.In this paper,we continue with the study on the relationship between properties defined with real-valued functions and some covering properties.Some characterizations of countably compact spaces and pseudo-compact spaces in terms of real-valued functions are obtained.     

Group averaging for de Sitter free fields in terms of hyperspherical functions

We study the convergence of inner products of free fields over the homogeneous spaces of the de Sitter group and show that the convergence of inner products in the case of N-particle states is defined by the asymptotic behavior of hypergeometric functions. We calculate the inner product for two-particle states on the four-dimensional hyperboloid in detail.     

Hardy空间的等价刻画

设Ｇ为局部域Ｋ上的２ｎ＋１维Ｈｅｉｓｅｎｂｅｒｇ群．本文证明了通过各种极大函数定义的Ｈａｒｄｙ空间的等价性，给出了Ｈａｒｄｙ空间的原子分解．利用这些等价定义及一些卷积算子定理，给出了Ｈａｒｄｙ空间的平方函数刻画——Ｌｕｚｉｎ面积函数刻画与Ｌｉｔｌｅｗｏｏｄ－Ｐａｌｅｙ平方函数刻画     

Duality in Vector Optimization Under Type 1 α-Invexity in Banach Spaces

The aim of this paper is to provide global optimality conditions and duality results for a class of nonconvex vector optimization problems posed on Banach spaces. In this paper, we introduce the concept of quasi type I α-invex, pseudo type I α-invex, quasi pseudo type I α-invex, and pseudo quasi type I α-invex functions in the setting of Banach spaces, and we consider a vector optimization problem with functions defined on Banach spaces. A few sufficient optimality conditions are given, and some results on duality are proved.