共查询到20条相似文献,搜索用时 31 毫秒
1.
The objective of the present paper is to find new sufficient conditions for the existence of unique strong solutions to a class of (time-inhomogeneous) stochastic differential equations with random, non-Lipschitzian coefficients. We give an example to show that our conditions are indeed weaker than those relevant conditions existing in the literature. We also derive moment estimations for the maximum process of the solution. Finally, we present a sufficient condition to ensure the non confluence property of the solution of time-homogeneous SDE which, in one dimension, is nothing but stochastic monotone property of the solution. 相似文献
2.
Frank Niedermeyer Saharon Shelah Karsten Steffens 《Archive for Mathematical Logic》2006,45(6):665-672
If P is a hereditary property then we show that, for the existence of a perfect f-factor, P is a sufficient condition for countable graphs and yields a sufficient condition for graphs of size ℵ1. Further we give two examples of a hereditary property which is even necessary for the existence of a perfect f-factor. We also discuss the ℵ2-case.This paper was supported by the Volkswagen Stiftung 相似文献
3.
4.
Yi Lin 《Advances in Mathematics》2007,208(2):699-709
In this paper we construct six-dimensional compact non-Kähler Hamiltonian circle manifolds which satisfy the strong Lefschetz property themselves but nevertheless have a non-Lefschetz symplectic quotient. This provides the first known counterexamples to the question whether the strong Lefschetz property descends to the symplectic quotient. We also give examples of Hamiltonian strong Lefschetz circle manifolds which have a non-Lefschetz fixed point submanifold. In addition, we establish a sufficient and necessary condition for a finitely presentable group to be the fundamental group of a strong Lefschetz manifold. We then use it to show the existence of Lefschetz four-manifolds with non-Lefschetz finite covering spaces. 相似文献
5.
在(CPS)_C及(PS)_C条件下,利用Ambrosetti-Rabinowitz对称形式的山路引理,研究了一类二阶哈密尔顿保守系统在给定能量面上的无穷多个周期解的存在性问题. 相似文献
6.
S. K. Kaushik 《Journal of Contemporary Mathematical Analysis (Armenian Academy of Sciences)》2009,44(4):212-218
Fusion Banach frames satisfying property S have been studied. A sufficient condition for the existence of a fusion Banach frame satisfying property S in weakly compactly generated Banach spaces has been given. Also, a necessary and sufficient condition for a fusion Banach
frame to satisfy property S has been given. Finally, fusion Banach frames satisfying property S have been characterized in terms of closedness of certain subspaces of the dual spaces in the weak*-topology. 相似文献
7.
基于已有的集值映射的弱次微分的概念,定义了集值映射的Henig全局次微分,研究了它的存在性条件以及运算性质.利用这一概念,分别给出了具约束向量集值最优化问题的Henig全局有效解对的必要性条件和充分性条件. 相似文献
8.
Georges Haddad 《Israel Journal of Mathematics》1981,39(1-2):83-100
The paper gives a necessary and sufficient condition for the existence of monotone trajectories to differential inclusionsdx/dt ∈S[x(t)] defined on a locally compact subsetX ofR
p, the monotonicity being related to a given preorder onX. This result is then extended to functional differential inclusions with memory which are the multivalued case to retarded
functional differential equations. We give a similar necessary and sufficient condition for the existence of trajectories
which reach a given closed set at timet=0 and stay in it with the monotonicity property fort≧0. 相似文献
9.
Summary Markov branching processes with instantaneous immigration possess the property that immigration occurs immediately the number of particles reaches zero, i.e. the conditional expectation of sojourn time at zero is zero. In this paper we consider the existence and uniqueness of such a structure. We prove that if the sum of the immigration rates is finite then no such structure can exist, and we provide a necessary and sufficient condition for existence for the case in which this sum is infinite. Study of the uniqueness problem shows that for honest processes the solution is unique. 相似文献
10.
The purpose of this note is to give an example of a rank-4 matroid which not only shows that Levi's intersection property is not a sufficient condition for the existence of an adjoint but also seems to have an interesting structure of the lattice of flats. 相似文献
11.
Immo Diener 《Discrete Mathematics》1982,39(3):283-292
In this paper we investigate the structure of S-cyclic Steiner quadruple systems and derive a necessary condition on thier existence which might turn out to be sufficient. In the third chapter we prove a necessary condition on the existence of general S-cyclic Steiner systems. It turns out that S-cyclicityis a very restrictive property that hardly any systems with t ≠ 3 can have. 相似文献
12.
This paper investigates the existence of absolute optimal solutions for a partition P in continuous and quasiconcave games. We show that the P-consistency property introduced in the paper, together with the quasiconcavity and continuity of payoffs, permits the existence of P-absolute optimal solutions in games with compact and convex strategy spaces. The P-consistency property is a general condition that cannot be dispensed with for the existence of P-absolute optimal solutions. We also characterize the existence of P-absolute optimal solutions by providing necessary and sufficient conditions. Moreover, we suggest an algorithm for efficiently computing P-absolute optimal solutions. 相似文献
13.
We give necessary and sufficient conditions for the total positivity of certain connection matrices arising in piecewise exponential
spline spaces. These total positivity conditions are sufficient for existence of B-splines in such spaces, but they are far
from being necessary. We give a necessary and sufficient condition for existence of B-splines in the case of piecewise exponential
spline spaces with only two differential operators, which eventually leads to a necessary condition for any piecewise exponential
spline spaces.
Dedicated to Professor Charles A. Micchelli for his 60th birthday
Mathematics subject classifications (2000) 65D17, 65D07, 41A15, 41A50. 相似文献
14.
文华艳 《数学的实践与认识》2017,(14):299-304
得到动力系统不具有d-跟踪性质和d-跟踪性质的一个充分条件.从而改进了文献[Journal of Difference Equations and Applications,16(2010):1131-1140]的定理3.1.同时证明Proximal系统必然具有d-跟踪性质.作为推论,得到存在具有d-跟踪性质的满支系统,其只含一个几乎周期点. 相似文献
15.
Cauchy's Problem for Degenerate Quasilinear Hyperbolic Equations with Measures as Initial Values 下载免费PDF全文
Hongjun Yuan 《偏微分方程(英文版)》1999,12(2):149-178
The aim of this paper is to discuss the Cauchy problem for degenerate quasilinear hyperbolic equations of the form \frac{∂u}{∂t} + \frac{∂u^m}{∂x} = -u^p, m > 1, p > 0 with measures as initial conditions. The existence and uniqueness of solutions are obtained. In particular, we prove the following results: (1) 0 < p < 1 is a necessary and sufficient condition for the above equations to have extinction property; (2) 0 < p < m is a necessary and sufficient condition for the above equations to have localization property of the propagation of perturbations. 相似文献
16.
Shin-ya Matsushita Wataru Takahashi 《Journal of Mathematical Analysis and Applications》2006,323(2):1354-1364
This paper is devoted to the investigation on the existence of zeros of monotone operators in reflexive Banach spaces. We first present a sufficient condition under which single-valued monotone operators have zeros. The obtained theorem includes a previous result as a special case. A necessary and sufficient condition for the existence of zeros of maximal monotone operators is presented. 相似文献
17.
在赋Orlicz范数的Orlicz空间中,给出最佳逼近算子单调性的一个充分条件和最佳逼近元存在定理. 相似文献
18.
F. Lara 《Optimization》2017,66(8):1259-1272
In this paper, we use generalized asymptotic functions and second-order asymptotic cones to develop a general existence result for the nonemptiness of the proper efficient solution set and a sufficient condition for the domination property in nonconvex multiobjective optimization problems. A new necessary condition for a point to be efficient or weakly efficient solution is given without any convexity assumption. We also provide a finer outer estimate for the asymptotic cone of the weakly efficient solution set in the quasiconvex case. Finally, we apply our results to the linear fractional multiobjective optimization problem. 相似文献
19.
Quanguo Chen & Jiangang Tang 《数学研究通讯:英文版》2012,28(4):289-299
We prove a Maschke type theorem for Doi-Hopf $π$-modules. A sufficient
condition for having a Maschke type property is that there exists a suitable total
integral map for the Doi-Hopf $π$-modules in question. The applications of the results
are considered. Finally, As an application of the existence of total integral, we prove
that $\mathop⊕ \limits_{α∈π} C_α ⊗ A$ is a generator in the category $^{π-C} U(H)A$. 相似文献
20.
OntheBestApproximationinNon-ArchimedeanNormedLinearSpacesonWeidun(邱维敦)(DepartmentofMathematics,LongyonNormalCollege,Fujian,36... 相似文献