On One Class of Subadditive Operators with Generalized Shift

Ukrainian Mathematical Journal - We establish strong and weak Hardy–Littlewood–Sobolev inequalities for the subadditive operators majorized by operators from a certain class of integral...     

Characterizations of generalized convexities via generalized directional derivatives

The paper gives characterizations of convexity, quasiconvexity, invexity and pseudoconvexity for a (radially) upper-semicontinuous function f in a topological vector space via appropriate properties of a bifunction which is majorized by the upper radial derivative of f and which stands for a generalized derivative of some sort.     

Homogeneous weak solenoids

A (generalized) weak solenoid is an inverse limit space over manifolds with bonding maps that are covering maps. If the covering maps are regular, then we call the inverse limit space a strong solenoid. By a theorem of M.C. McCord, strong solenoids are homogeneous. We show conversely that homogeneous weak solenoids are topologically equivalent to strong solenoids. We also give an example of a weak solenoid that has simply connected path-components, but which is not homogeneous.

     

新优化的Hilbert积分不等式

推广、改进并给出了某些新的重要Hilbert积发不等式。     

乘积FC-空间内涉及——较好容许集值映象的优化映象族的极大元及其应用

引入了涉及-较好容许集值映象的映-拓扑空间到-有限连续拓扑空间（简称，FC-空间）的优化映象族．在乘积FC-空间的非紧设置下埘这类优化映象族证明了某些极大元存在性定理．在乘积FC-空间内给出了对不动点和极小极大不等式组的应用．这些定理改进、统一和推广了最近文献中的很多重要结果．     

乘积FC-空间内涉及一较好容许集值映象的优化映象族的极大元及其应用

引入了涉及一较好容许集值映象的映一拓扑空间到一有限连续拓扑空间(简称,FC-空间)的优化映象族．在乘积FC-空间的非紧设置下对这类优化映象族证明了某些极大元存在性定理．在乘积FC-空间内给出了对不动点和极小极大不等式组的应用．这些定理改进、统一和推广了最近文献中的很多重要结果．     

对一道积分不等式题的再思考

利用提升维度的方法并结合几何图形直观分析,给出一道一元函数积分均值不等式的新证明,并将原不等式推广至形式较为对称的不等式,使得原不等式成为新不等式的特例.最后证明新不等式与函数单调递减的定义等价.     

Loeb空间上一类右连续过程最优停止的非标准表示

本文在Loeb空间上得到了右连续左半上连续的随机过程的SRC提升．证明了一个内过程的S-最优停止的存在性,并得到了它的结构性表示．最后证明了一个过程SRC提升的S-最优停止的标准部分即为对应标准过程的最优停止,在Loeb空间上推广了[8]中的结果．     

Loeb空间上一类右连续过程最优停止的非标准表示

本文在Loeb空间上得到了右连续左半上连续的随机过程的SRC提升．证明了一个内过程的S-最优停止的存在性,并得到了它的结构性表示．最后证明了一个过程SRC提升的S-最优停止的标准部分即为对应标准过程的最优停止,在Loeb空间上推广了[8]中的结果．     

On a Kantorovich Problem with a Density Constraint

The Kantorovich optimal transport problemwith a density constraint onmeasures on an infinite-dimensional space is considered. In this setting, the admissible transport plan is nonnegative and majorized by a given constraint function. The existence and the uniqueness of a solution of this problem are proved.     

Henstock-Kurzweil-Pettis integral and weak topologies in nonlinear integral equations on time scales

The goal of the present work is to give an existence result for a nonlinear integral equation on time scales by considering the Banach space endowed with its weak topology. More precisely, we obtain the existence of weakly continuous solutions for an integral equation that has on the right hand side the sum of two operators, one of them continuous while the other one satisfies a partial continuity condition and some integrability (in a nonabsolute sense) assumptions.     

The Method of Upper and Lower Solutions of Stochastic Differential Equations and Applications

Abstract

The purpose of this article is to consider a stochastic integral equation driven by semimartingale with discontinuous and increasing drift part. We discuss the existence of strong solutions using lower and upper solutions method and a fixed point theorem for ordered topological space. Finally we present some applications in finance.     

Upper integral and its geometric meaning

The Hahn definition of the integral is recalled, the requirement of measurability of the integrand omitted. Both the upper and lower integrals comply with this definition and so does any measurable function between them. The outer product measure of the hypograph of a nonnegative bounded nonmeasurable function is equal to the upper integral which is equal to one of the Fan integrals. The outer measure of the graph of a bounded nonmeasurable function is equal to the difference between the upper and lower integrals. A norm for not necessarily measurable functions is defined with the upper integral. The linear space with this norm is complete. The convergence in this space implies the convergence in outer measure. The distance as an outer measure of the symmetric difference of two sets gives us a complete metric space of classes of subsets.      

Multifibrations. A Class of Shape Fibrations with the Path Lifting Property

In this paper we introduce a class of maps possessing a multivalued homotopy lifting property with respect to every topological space. We call these maps multifibrations and they represent a formally stronger concept than that of shape fibration. Multifibrations have the interesting property of being characterized in a completely intrinsic way by a path lifting property involving only the total and the base space of the fibration. We also show that multifibrations (and also, with some restrictions, shape fibrations) have a lifting property for homotopies of fine multivalued maps. This implies, when the spaces considered are metric compacta, that the possibility of lifting a fine multivalued map is a property of the corresponding strong shape morphism and not of the particular map considered.     

The weak McShane integral

We present a weaker version of the Fremlin generalized McShane integral (1995) for functions defined on a σ-finite outer regular quasi Radon measure space (S,Σ, T, µ) into a Banach space X and study its relation with the Pettis integral. In accordance with this new method of integration, the resulting integral can be expressed as a limit of McShane sums with respect to the weak topology. It is shown that a function f from S into X is weakly McShane integrable on each measurable subset of S if and only if it is Pettis and weakly McShane integrable on S. On the other hand, we prove that if an X-valued function is weakly McShane integrable on S, then it is Pettis integrable on each member of an increasing sequence (S _l ) _l?1 of measurable sets of finite measure with union S. For weakly sequentially complete spaces or for spaces that do not contain a copy of c ₀, a weakly McShane integrable function on S is always Pettis integrable. A class of functions that are weakly McShane integrable on S but not Pettis integrable is included.     

Reduction principle for a certain class of kernel-type operators

The classical Hardy–Littlewood inequality asserts that the integral of a product of two functions is always majorized by that of their non-increasing rearrangements. One of the pivotal applications of this result is the fact that the boundedness of an integral operator acting near zero is equivalent to the boundedness of the same operator restricted to the cone of positive non-increasing functions. It is well known that an analogous inequality for integration away from zero is not true. We will show in this paper that, nevertheless, the equivalence of the two inequalities is still preserved for certain rather general class of kernel-type operators under a mild restriction and regardless of the measure of the underlying integration domain.     

An orthogonal approach to algebraic weak factorisation systems

We describe an equivalent formulation of algebraic weak factorisation systems, not involving monads and comonads, but involving double categories of morphisms equipped with a lifting operation satisfying lifting and factorisation axioms.     

The homological singularities of maps in trace spaces between manifolds

We deal with mappings defined between Riemannian manifolds that belong to a trace space of Sobolev functions. The homological singularities of any such map are represented by a current defined in terms of the boundary of its graph. Under suitable topological assumptions on the domain and target manifolds, we show that the non triviality of the singular current is the only obstruction to the strong density of smooth maps. Moreover, we obtain an upper bound for the minimal integral connection of the singular current that depends on the fractional norm of the mapping.     

Schur凸函数与n维单形不等式

应用Schur函数理论研究几何不等式,借助n维单形及p维子单形中的优超关系,在n维欧氏空间给出Petrovic不等式,Darling-Moser不等式及Finsler-Hadwiger不等式的几种推广形式。     

Strong liftings with application to measurable cross sections in locally compact groups

There are two principal theorems. The adjustment theorem asserts that a lifting may be changed on a set of measure zero so as to become slightly stronger. In conjunction with the standard lifting theorem, it yields generalizations (with shorter proofs) of a number of known results in the theory of strong liftings. It also inspires a characterization of strong liftings, when the measure is regular, by the fact that they induce upon every open set an artificial “closure” of that set which differs from it by a set of measure zero. The projection theorem asserts that, in the presence of a strict disintegration, a strong lifting may be transferred or “projected” from one topological measure space onto another. In conjunction with Losert's example, it yields regular Borel, measures, carried on compact Hausdorff spaces of arbitrarily large weight, which everywhere fail to have the strong lifting property. It also provides the final link needed to obtained, with no separability assumptions, a measurable cross section (or right inverse) for the canonical map Ω:G→G/H, whereG is an arbitrary locally compact group, and whereH is an arbitrary closed subgroup ofG.