986 research outputs found

    Parametric representation of univalent functions with boundary regular fixed points

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    Given a set S\mathfrak S of conformal maps of the unit disk D\mathbb D into itself that is closed under composition, we address the question whether S\mathfrak S can be represented as the reachable set of a Loewner - Kufarev - type ODE dwt/dt=Gtwt\mathrm{d}w_t/\mathrm{d}t=G_t\circ w_t, w0=idDw_0=\mathsf{id}_{\mathbb D}, where the control functions tGtt\mapsto G_t form a convex cone MS\mathcal M_{\mathfrak S}. For the set of all conformal φ:DD\varphi:\mathbb D\to\mathbb D with φ(0)=0\varphi(0)=0, φ(0)>0\varphi'(0)>0, an affirmative answer to this question is the essence of Loewner's well-known Parametric Representation of univalent functions [Math. Ann. 89 (1923), 103-121]. In this paper, we study classes of conformal self-maps defined by their boundary regular fixed points and, in part of the cases, establish their Loewner-type representability.Comment: Version 3: Introduction has been modified; Example 3.1 added + other minor correction

    Angular and unrestricted limits of one-parameter semigroups in the unit disk

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    We study local boundary behaviour of one-parameter semigroups of holomorphic functions in the unit disk. Earlier under some addition condition (the position of the Denjoy - Wolff point) it was shown in [M.D.Contreras, S.Diaz-Madrigal and Ch.Pommerenke, Ann. Acad. Sci. Fenn. Math. 29(2004), No.2, 471-488] that elements of one-parameter semigroups have angular limits everywhere on the unit circle and unrestricted limits at all boundary fixed points. We prove stronger versions of these statements with no assumption on the position of the Denjoy - Wolff point. In contrast to many other problems, in the question of existence for unrestricted limits it appears to be more complicated to deal with the boundary Denjoy - Wolff point (the case not covered in [M.D.Contreras, S.Diaz-Madrigal and Ch.Pommerenke, Ann. Acad. Sci. Fenn. Math. 29(2004), No.2, 471-488]) than with all the other boundary fixed points of the semigroup.Comment: Some changes are made in this version: misprints and minor errors are corrected, the information on the grant support is adde

    Ірраціональні вірування людини як когнітивні утворення. (Irrational beliefs of personality as cognitive formation)

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    В статті досліджено психологічні особливості такого конструкту, як «ірраціональні вірування людини», охарактеризовано розуміння життєвих труднощів з точки зору когнітивної парадигми, подано ключові ірраціональні вірування сучасної вітчизняної вибірки, обґрунтовано доцільність вживання терміну «вірування» в контексті різних форм дисфункціональних когніцій людини.(An article researches psychological peculiarities of “human irrational beliefs” construct, describes cognitive approach to understanding of life difficulties, gives core irrational beliefs of contemporary national sample, explains necessity of using a construct of ‘beliefs’ in the context of different forms of human dysfunctional cognitions.

    Valiron and Abel equations for holomorphic self-maps of the polydisc

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    We introduce a notion of hyperbolicity and parabolicity for a holomorphic self-map f:ΔNΔNf: \Delta^N \to \Delta^N of the polydisc which does not admit fixed points in ΔN\Delta^N. We generalize to the polydisc two classical one-variable results: we solve the Valiron equation for a hyperbolic ff and the Abel equation for a parabolic nonzero-step ff. This is done by studying the canonical Kobayashi hyperbolic semi-model of ff and by obtaining a normal form for the automorphisms of the polydisc. In the case of the Valiron equation we also describe the space of all solutions.Comment: A few references are adde

    Matching univalent functions and conformal welding

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    Given a conformal mapping ff of the unit disk D\mathbb D onto a simply connected domain DD in the complex plane bounded by a closed Jordan curve, we consider the problem of constructing a matching conformal mapping, i.e., the mapping of the exterior of the unit disk D\mathbb D^* onto the exterior domain DD^* regarding to DD. The answer is expressed in terms of a linear differential equation with a driving term given as the kernel of an operator dependent on the original mapping ff. Examples are provided. This study is related to the problem of conformal welding and to representation of the Virasoro algebra in the space of univalent functions.Comment: 17 page

    Transport connectivity as a factor in overcoming challenges of the periphery: the case of rural areas in the Kaliningrad region

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    Quality of life in rural areas is increasingly dependent on transport links to nearest towns and regional centres. In this article, we examine transport connectivity between villages and towns in the Kaliningrad region. We use the travel time access parameter to investigate the influence of transport connectivity on the population size and the prospects of socio-economic development in rural areas with different transport and geographical situations. Although the overall transport connectivity is high in the region, up to 10 per cent of villages score low on this parameter. We conclude that the demographic saturation of the Kaliningrad agglomeration has not been completed. Moreover, the smallness of the local consumer market impedes the formation of subregional centres in the eastern part of the region. The most alarming trend is the incipient concentration of population in peripheral border areas
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