A generalization of Hahn-Banach extension theorem

In this paper, the notion of affinelike set-valued maps is introduced and some properties of these maps are presented. Then a new Hahn-Banach extension theorem with a K-convex set-valued map dominated by an affinelike set-valued map is obtained.     

Integer-valued characteristics of solutions of the noncommutative sigma model

Any finite-energy solution of a noncommutative sigma model has three nonnegative integer-valued characteristics: the normalized energy e(Φ), canonical rank r(Φ), and minimum uniton number u(Φ). We prove that r(Φ) ≥ u(Φ) and e(Φ) ≥ u(Φ)(u(Φ) + 1)/2. Given any numbers e, r, u ∈ ? that satisfy the slightly stronger inequalities r ≥ u and e ≥ r +u(u ? 1)/2, we construct a finite-energy solution Φ with e(Φ) = e, r(Φ) = r, and u(Φ) = u.     

Geometry and entropy of generalized rotation sets

For a continuous map f on a compact metric space we study the geometry and entropy of the generalized rotation set Rot(Φ). Here Φ = (?₁, ..., ? _m ) is a m-dimensional continuous potential and Rot(Φ) is the set of all µ-integrals of Φ and µ runs over all f-invariant probability measures. It is easy to see that the rotation set is a compact and convex subset of ? ^m . We study the question if every compact and convex set is attained as a rotation set of a particular set of potentials within a particular class of dynamical systems. We give a positive answer in the case of subshifts of finite type by constructing for every compact and convex set K in ? ^m a potential Φ = Φ(K) with Rot(Φ) = K. Next, we study the relation between Rot(Φ) and the set of all statistical limits Rot _Pt (Φ). We show that in general these sets differ but also provide criteria that guarantee Rot(Φ) = Rot _Pt (Φ). Finally, we study the entropy function w ? H(w),w ∈ Rot(Φ). We establish a variational principle for the entropy function and show that for certain non-uniformly hyperbolic systems H(w) is determined by the growth rate of those hyperbolic periodic orbits whose Φ-integrals are close to w. We also show that for systems with strong thermodynamic properties (sub-shifts of finite type, hyperbolic systems and expansive homeomorphisms with specification, etc.) the entropy function w ? H(w) is real-analytic in the interior of the rotation set.     

Spaces of lower semicontinuous set-valued maps

We give a negative answer to Problem 2 posed by R. A. McCoy in his paper [McCoy R. A.: Spaces of lower semicontinuous set-valued maps II, Math. Slovaca 60 (2010), 541–570]. Some topological properties of the space L ^?(X) introduced in [McCOY R. A.: Spaces of lower semicontinuous set-valued maps I, Math. Slovaca 60 (2010), 521–540] equipped with the Vietoris topology are also investigated.     

On polynomial digraphs

Let Φ(x,y) be a bivariate polynomial with complex coefficients. The zeroes of Φ(x,y) are given a combinatorial structure by considering them as arcs of a directed graph G(Φ). This paper studies some relationship between the polynomial Φ(x,y) and the structure of G(Φ).     

集值终上鞅的一个收敛定理

it In this paper, the properties of set-valued Eventual Supermartingle are dis-cussed. The main result is that suppose {Fn, n≥1} L1fc(X) be set-valued Eventual Supermaxtingle, if sup E(d(0, Fr)) < ∞, then Fn→F and S1F≠Φ, here T is the sets of all bounded stopping times.     

Embeddings between weak Orlicz martingale spaces

Let Φ be an increasing and convex function on [0,∞) with Φ(0)=0 satisfying that for any α>0, there exists a positive constant Cα such that Φ(αt)?CαΦ(t), t>0. Let wLΦ denote the corresponding weak Orlicz space. We obtain some embeddings between vector-valued weak Orlicz martingale spaces by establishing the wLΦ-inequalities for martingale transform operators with operator-valued multiplying sequences. These embeddings are closely related to the geometric properties of the underlying Banach space. In particular, for any scalar valued martingale f=(fn)_n?1, we claim that

     

An inertial proximal scheme for nonmonotone mappings

We present an inertial proximal method for solving an inclusion involving a nonmonotone set-valued mapping enjoying some regularity properties. More precisely, we investigate the local convergence of an implicit scheme for solving inclusions of the type T(x)∋0 where T is a set-valued mapping acting from a Banach space into itself. We consider subsequently the case when T is strongly metrically subregular, metrically regular and strongly regular around a solution to the inclusion. Finally, we study the convergence of our algorithm under variational perturbations.     

Multiobjective programming with new invexities

(Φ, ρ)-invexity and (Φ, ρ) ^w -invexity generalize known invexity type properties and have been introduced with the intent of extending most of theoretical results in mathematical programming. Here, we push this approach further, to obtain authentic extensions of previously known optimality and duality results in multiobjective programming.     

On optimization problems with set-valued objective maps

In this paper, we consider constrained optimization problems with set-valued objective maps. First, we define three types of quasi orderings on the set of all non-empty subsets in n-dimensional Euclidean space and investigate their properties. Next, by using these orderings, we define the concepts of the convexities to set-valued maps and investigate their properties. Finally, based on these results, we define the concepts of optimal solutions to constrained optimization problems with set-valued objective maps and characterize their properties.     

Metric subregularity of order <Emphasis Type="Italic">q</Emphasis> and the solving of inclusions

We consider some metric regularity properties of order q for set-valued mappings and we establish several characterizations of these concepts in terms of Hölder-like properties of the inverses of the mappings considered. In addition, we show that even if these properties are weaker than the classical notions of regularity for set-valued maps, they allow us to solve variational inclusions under mild assumptions.     

Strong solution of Itô type set-valued stochastic differential equation

In this paper, we shall firstly illustrate why we should introduce an It5 type set-valued stochastic differential equation and why we should notice the almost everywhere problem. Secondly we shall give a clear definition of Aumann type Lebesgue integral and prove the measurability of the Lebesgue integral of set-valued stochastic processes with respect to time t. Then we shall present some new properties, especially prove an important inequality of set-valued Lebesgue integrals. Finally we shall prove the existence and the uniqueness of a strong solution to the It5 type set-valued stochastic differential equation.     

Uniformity and inexact version of a proximal method for metrically regular mappings

We study stability properties of a proximal point algorithm for solving the inclusion 0∈T(x) when T is a set-valued mapping that is not necessarily monotone. More precisely we show that the convergence of our algorithm is uniform, in the sense that it is stable under small perturbations whenever the set-valued mapping T is metrically regular at a given solution. We present also an inexact proximal point method for strongly metrically subregular mappings and show that it is super-linearly convergent to a solution to the inclusion 0∈T(x).     

Remarks on semilinear partial functional-differential equations with infinite delay

In this paper we will be concerned with the abstract semilinear equation x(Φ)(t) = Ax(Φ)(t) + F(t, x_t(Φ)), t ? τ, x_τ(Φ) = Φ, where A represents the infinitesimal generator of a linear C₀-semigroup in a Banach space and x_～(Φ) denotes the segment of the solution x due to the initial function Φ taken from ?∞ up to t. Conditions for existence, continuous dependence, and regularity of solutions are given which are independent of the topology of the phase space, as well as conditions which guarantee the compactness of bounded orbits, even if exp(At) is not compact for t > 0.     

Multiple solutions of two-point nonlinear boundary value problems

A quasi-linear boundary value problem has a solution with properties induced by oscillatory properties of the linear part of an equation. This result is proved for two dimensional systems. Consequences for Φ-Laplacian equations and problems with resonant linear parts are discussed.     

Existence and uniqueness of endpoints of closed set-valued asymptotic contractions in metric spaces

Investigations of problems of set-valued asymptotic fixed point theory of set-valued dynamic systems are initiated. The concepts of the set-valued asymptotic contractions of set-valued dynamic systems in metric space M are introduced and conditions guaranteeing the existence and uniqueness of endpoints v∈M of set-valued dynamic systems of set-valued asymptotic contractions and convergence to v of all generalized sequences of iterations of T are established. Examples and remarks show a fundamental difference between our results and the well-known ones.     

Irreducible circuits and Coxeter arrangements

We introduce the concept of irreducible circuits. In a vector arrangement Φ, these are configurations consisting of one vector α∈Φ in the positive linear span of an independent set Δ⊂Φ such that no proper subset of Δ has any member of Φ−Δ in its positive linear span. We show that the oriented matroid of any centrally symmetric vector arrangement is constructively determined by its irreducible circuits, and classify the irreducible circuits in root systems.     

The gradient and heavy ball with friction dynamical systems: the quasiconvex case

We consider the gradient system $\dot x(t)+\nabla\phi(x(t))=0$ and the so-called heavy ball with friction dynamical system $\ddot x(t) +\lambda\dot x(t)+\nabla\phi(x(t))=0$ , as well as an implicit discrete (proximal) version of it, and study the asymptotic behavior of their solutions in the case of a smooth and quasiconvex objective function Φ. Minimization properties of trajectories are obtained under various additional assumptions. We finally show a minimizing property of the heavy ball method which is not shared by the gradient method: the genericity of the convergence of each trajectory, at least when Φ is a Morse function, towards local minimum of Φ.