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1.
By applying the technique of continuous partition of unity, some new coincidence theorems for a better admissible mapping and a family of set-valued mappings defined on the product G-convex spaces are proved. Theorems of this paper improve, unify and generalize many important coincidence theorems and collectively fixed point theorems in recent literature.  相似文献   

2.
In this paper, the authors establish distortion theorems for various subfamilies Hk(B) of holomorphic mappings defined in the unit ball in Cn with critical points, where k is any positive integer. In particular, the distortion theorem for locally biholomorphic mappings is obtained when k tends to oo. These distortion theorems give lower bound son det f(z) and Redet f'(z). As an application of these distortion theorems, the authors give lower and upper bounds of Bloch constants for the subfamilies βk (M) of holomorphic mappings. Moreover, these distortion theorems are sharp. When B is the unit disk in C, these theorems reduce to the results of Liu and Minda. A new distortion result of Re det f'(z) for locally biholomorphic mappings is also obtained.  相似文献   

3.
侯吉成 《东北数学》2008,24(3):207-218
In this paper, we first prove some new selection and fixed point theorems in generalized convex spaces. Then, we establish some existence theorems of quasi-equilibrium and generalized quasi-equilibrium without the conditions of open fibers, by applying our selection and fixed point theorems.  相似文献   

4.
In this paper we generalize the notions of weight,character, density and cellularity of topological spaces to L-fuzzy topogical spaces. We prove theorems corresponding to some of usual theorems. In pa-  相似文献   

5.
We introduce the concept of a weakly G-quasiconvex map with respect to a map on generalized convex spaces and use the concept to prove coincidence point theorems and almost-like coincidence point theorems. As applications of the above results, we derive almost fixed point theorems and fixed point theorem. These main results generalize and improve some known results in the literature.  相似文献   

6.
APPROXIMATION ORDER AND INTERPOLATION SPACES   总被引:1,自引:0,他引:1  
In this paper we introduce the two-parameter operators on Abelian group and establish their interpolation theorems of approximation, which are extensions of the interpolation theorems for nonlinear best approximation by R. Devore and are suitable for the approximation of oprators.  相似文献   

7.
QUALITATIVE ANALYSIS FOR A CLASS OF NONLINEAR DIFFERENTIAL EQUATIONS   总被引:4,自引:0,他引:4  
In this paper, we give some theorems on existence of periodic solutions for a class of nonlinear differential equations. A concise expression about the bounds of time-delay is obtained, these theorems include some well-known results as their special cases.  相似文献   

8.
A local convergence theorem and five semi-local convergence theorems of the secant method are listed in this paper.For every convergence theorem,a convergence ball is respectively introduced,where the hypothesis conditions of the corresponding theorem can be satisfied.Since all of these convergence balls have the same center x~*,they can be viewed as a homocentric ball. Convergence theorems are sorted by the different sizes of various radii of this homocentric ball, and the sorted sequence represents the degree of weakness on the conditions of convergence theorems.  相似文献   

9.
In this paper we present a general probabilistic representation theorem for semigroups of operators which essentially comprises almost all known representation theorems of this kind.Especially,so-called first and second main theorems turn out to be special cases of the same general formula. The general theorem also permits the calculation of rates of convergence involving the second modulus of continuity.  相似文献   

10.
This paper is divided into two parts, where the general regularities of information flow in the tree graph are discussed. In the first part we discuss the equivalent theorems of the tree flow, the main sections are as follows: 1. fundamental definitions; 2. equivalent mapping structure; 3. equivalent partition of vector set*; 4. theorems of tree flow. And in the second part we put stress on the establishment of tree flow equations.Here we present two most essential streams of information flowing in the tree, i.e. characteristic information flow F* and equivalent characteristic information flow *θ~κ (?), therefore the interior relation in tree flow is explicited.The main conclusions in this paper are centralized in three theorems, they are respectively called tree flow theorem, tree flow theorem A and tree flow theorem B. The first theorem describes the equivalent partition of tree flow and the latter theorems then describe the equations of tree flow. The basis of establishing these theorems is just th  相似文献   

11.
In this paper we use the real differential geometric definition of a metric (a unimodular oriented metric) tt*-bundle of Cortés and the author (Topological-anti-topological fusion equations, pluriharmonic maps and special Kähler manifolds) to define a map Φ from the space of metric (unimodular oriented metric) tt*-bundles of rank r over a complex manifold M to the space of pluriharmonic maps from M to {GL}(r)/O(p,q) (respectively {SL}(r)/SO(p,q)), where (p,q) is the signature of the metric. In the sequel the image of the map Φ is characterized. It follows, that in signature (r,0) the image of Φ is the whole space of pluriharmonic maps. This generalizes a result of Dubrovin (Comm. Math. Phys. 152 (1992; S539–S564).  相似文献   

12.
For any 0 < ? < 1 one can find a measurable set E ? [0, 1] with the measure |E| > 1 ? ? such that for each function f(x) ε L 1 (0, 1) a function g(x) ε L 1 (0, 1) exists such that it coincides with f (x) on E, its Fourier—Walsh series converges to it in the metric of L 1 (0, 1), and all nonzero terms of the sequence of Fourier coefficients of the new function obtained by the Walsh system have the modulo decreasing order; consequently, the greedy algorithm for this function converges to it in the L 1 (0, 1)-norm.  相似文献   

13.
As shown in [1], for each compact Hausdorff space K without isolated points, there exists a compact Hausdorff P′-space X but not an F-space such that C(K) is isometrically Riesz isomorphic to a Riesz subspace of C(X). The proof is technical and depends heavily on some representation theorems. In this paper we give a simple and direct proof without any assumptions on isolated points. Some generalizations of these results are mentioned.  相似文献   

14.
We present an equivalence theorem, which includes all known characterizations of the class B p , i.e., the weight class of Ariño and Muckenhoupt, and also some new equivalent characterizations. We also give equivalent characterizations for the classes B p * , B * and RB p , and prove and apply a “gluing lemma” of independent interest.  相似文献   

15.
Local Tb theorems with L p type testing conditions, which are not scale invariant, have been studied widely in the case of the Lebesgue measure. In the non-homogeneous world local Tb theorems have only been proved assuming scale invariant (L or BMO) testing conditions. In this paper, for the first time, we overcome these obstacles in the non-homogeneous world, and prove a nonhomogeneous local Tb theorem with L 2 type testing conditions. This paper is in the setting of the vertical and conical square functions defined using general measures and kernels. On the technique side, we demonstrate a trick of inserting Calderón–Zygmund stopping data of a fixed function into the construction of the twisted martingale difference operators. This built-in control of averages is an alternative to Carleson embedding.  相似文献   

16.
In this paper LJ-spaces are introduced and studied. They are a common generalization of Lindelöf spaces and J-spaces researched by E. Michael. A space X is called an LJ-space if, whenever {A, B} is a closed cover of X with AB compact, then A or B is Lindelöf. Semi-strong LJ-spaces and strong LJ-spaces are also defined and investigated. It is demonstrated that the three spaces are different and have interesting properties and behaviors.  相似文献   

17.
Let G be a finite group and let Γ(G) be the prime graph of G. Assume p prime. We determine the finite groups G such that Γ(G) = Γ(PSL(2, p 2)) and prove that if p ≠ 2, 3, 7 is a prime then k(Γ(PSL(2, p 2))) = 2. We infer that if G is a finite group satisfying |G| = |PSL(2, p 2)| and Γ(G) = Γ(PSL(2, p 2)) then G ? PSL(2, p 2). This enables us to give new proofs for some theorems; e.g., a conjecture of W. Shi and J. Bi. Some applications are also considered of this result to the problem of recognition of finite groups by element orders.  相似文献   

18.
We present conditions that allow us to prove the existence of eigenvalues and characteristic values for operator F(D) ? C(λ): L 2(R m ) → L 2(R m ), where F(D) is a pseudo-differential operator with a symbol F() and C(λ): L 2(R m ) → L 2(R m ) is a linear continuous operator.  相似文献   

19.
A subgroup is called c-semipermutable in G if A has a minimal supplement T in G such that for every subgroup T 1 of T there is an element xT satisfying AT 1 x = T 1 x A. We obtain a few results about the c-semipermutable subgroups and use them to determine the structures of some finite groups.  相似文献   

20.
For integers nr, we treat the rth largest of a sample of size n as an \(\mathbb {R}^{\infty }\)-valued stochastic process in r which we denote as M(r). We show that the sequence regarded in this way satisfies the Markov property. We go on to study the asymptotic behavior of M(r) as r, and, borrowing from classical extreme value theory, show that left-tail domain of attraction conditions on the underlying distribution of the sample guarantee weak limits for both the range of M(r) and M(r) itself, after norming and centering. In continuous time, an analogous process Y(r) based on a two-dimensional Poisson process on \(\mathbb {R}_{+}\times \mathbb {R}\) is treated similarly, but we note that the continuous time problems have a distinctive additional feature: there are always infinitely many points below the rth highest point up to time t for any t >?0. This necessitates a different approach to the asymptotics in this case.  相似文献   

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