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1.
We introduce a method for constructing J-complex discs. The method only uses the standard scheme for solving the Beltrami equation and the Schauder principle. As an application, we give a short self-contained proof of Gromov's Non-Squeezing Theorem.  相似文献   

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In this paper, we survey some recent results on the existence of bounded plurisubharmonic functions on pseudoconvex domains, the Diederich–Forn?ss exponent and its relations with existence of domains with Levi-flat boundary in complex manifolds.  相似文献   

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Recently, Tedi Draghici and Weiyi Zhang studied Donaldson's "tamed to compatible" question (Draghici T, Zhang W. A note on exact forms on almost complex manifolds, arXiv: 1111. 7287vl [math. SC]. Submitted on 30 Nov. 2011). That is, for a compact almost complex 4-manifold whose almost complex structure is tamed by a symplectic form, is there a symplectic form compatible with this almost complex structure? They got several equivalent forms of this problem by studying the space of exact forms on such a manifold. With these equivalent forms, they proved a result which can be thought as a further partial answer to Donaldson's question in dimension 4. In this note, we give another simpler proof of their result.  相似文献   

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We obtain and apply a simple form of the integrability condition of an almost complex structure to the Hopf manifolds.  相似文献   

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This article deals with some boundary value problems for quasilinear mixed (elliptic-hyperbolic) complex equations of first order with degenerate hyperbolic curve in a simply connected domain. First, we give the representation theorem and prove the uniqueness of solutions for the above boundary value problems. Then using the method of successive iteration, the existence of solutions for the above problems is proved.  相似文献   

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Milan Journal of Mathematics - We define formally non characteristic hypersurfaces for a complex of differential operators and we establish a Mayer-Vietoris sequence. We give applications to...  相似文献   

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主要研究Clifford分析中hypergenic函数的边值问题A(y)Ψ*+f(y)+B(y)Ψ*-f(y)=G(y)L(Ψ*+f(y),Ψ*-f(y)).首先讨论hypergenic拟Cauchy型积分的相关性质;其次利用Schauder不动点原理证明了非线性边值问题解的存在性;最后利用压缩映射原理证明了线性边值问题解的存在唯一性.  相似文献   

11.
Boundary value problems with causal operators   总被引:1,自引:0,他引:1  
In this paper, we apply the monotone iterative method for nonlinear two-point boundary value problems with causal operators. We formulate sufficient conditions under which such problems have extremal or quasisolutions in a corresponding sector. We also investigate differential inequalities.  相似文献   

12.
We present two methods, both based on topological ideas, to the solvability of boundary value problems for differential equations and inclusions on infinite intervals. In the first one, related to the rich family of asymptotic problems, we generalize and extend some statements due to the Florence group of mathematicians Anichini, Cecchi, Conti, Furi, Marini, Pera, and Zecca. Thus, their conclusions for differential systems are as well true for inclusions; all under weaker assumptions (for example, the convexity restrictions in the Schauder linearization device can be avoided). In the second, dealing with the existence of bounded solutions on the positive ray, we follow and develop the ideas of Andres, Górniewicz, and Lewicka, who considered periodic problems. A special case of these results was previously announced by Andres. Besides that, the structure of solution sets is investigated. The case of l.s.c. right hand sides of differential inclusions and the implicit differential equations are also considered. The large list of references also includes some where different techniques (like the Conley index approach) have been applied for the same goal, allowing us to envision the full range of recent attacks on the problem stated in the title.

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13.
We consider the boundary value problems in the half-space for a class of quasielliptic systems with variable coefficients. Assuming that the boundary value problems satisfy the Lopatinski? condition, we establish sufficient conditions for unique solvability in Sobolev spaces.  相似文献   

14.
We present here a systematic study of general boundary value problems on weighted networks that includes the variational formulation of such problems. In particular, we obtain the discrete version of the Dirichlet Principle and we apply it to the analysis of the inverse problem of identifying the conductivities of the network in a very general framework. Our approach is based on the development of an efficient vector calculus on weighted networks which mimetizes the calculus in the smooth case. The key tool is an adequate construction of the tangent space at each vertex. This allows us to consider discrete vector fields, inner products and general metrics. Then, we obtain discrete versions of derivative, gradient, divergence and Laplace-Beltrami operators, satisfying analogous properties to those verified by their continuous counterparts. On the other hand we develop the corresponding integral calculus that includes the discrete versions of the Integration by Parts technique and Green’s Identities. Finally, we apply our discrete vector calculus to analyze the consistency of difference schemes used to solve numerically a Robin boundary value problem in a square.  相似文献   

15.
Recently complex function techniques have been developed for the analysis of queueing systems which need for their modelling a two dimensional state space. A variety of computer- and communication networks gives rise to such two-dimensional queueing systems and their analysis is needed for the performance evaluation of these aggregates. The present study reviews these developments  相似文献   

16.
This paper shows how certain regularization methods can be used to determine the solution structure of linear differential systems subject to linear constraints and boundary conditions. Attention is restricted to the relatively straightforward index-one problems and to certain index-two problems, where endpoint jumps are related to the underlying boundary layer structure of the corresponding singular perturbation problems.  相似文献   

17.
The behaviour of a Herschel-Bulkley material near the apex ofa semi-infinite plate is studied. The plate is immersed in thecentre of a longitudinal strip the sides of which are subjectedto equal and opposite velocities. The problem is consideredin the hodograph plane, where it is possible to obtain a solution.Transforming this solution back to the real plane yields anexact expansion of the velocity field near the apex of the plate.The leading term of the velocity field is checked by using aninvariant integral which involves the energy-momentum tensorof the system. A reciprocal theorem is also derived, wherebythe coefficient of the singular strain rate field at the plateedge is related to finite integrals in the hodograph plane.A check of this method is effected by comparison with the solutionof the above problem.  相似文献   

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Mathematical Institute, National Ukrainian Academy of Science. Translated from Funktsional'nyi Analiz i Ego Prilozheniya, Vol. 29, No. 3, pp. 87–90, July–September, 1995.  相似文献   

20.
In this paper we introduce an alternative way of defining the curvilinear Cauchy integral over non-rectifiable curves in the case of complex functions of one complex variable. Especially the jump behavior on the boundary is considered. As an application, solvability conditions of the Riemann boundary value problem are derived on very weak conditions to the boundary. Besides the complex case the consideration can be extended to the theory of Douglis algebra valued functions.  相似文献   

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