1,991 research outputs found

    A Phragm\'en-Lindel\"of theorem via proximate orders, and the propagation of asymptotics

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    We prove that, for asymptotically bounded holomorphic functions in a sector in C\mathbb{C}, an asymptotic expansion in a single direction towards the vertex with constraints in terms of a logarithmically convex sequence admitting a nonzero proximate order entails asymptotic expansion in the whole sector with control in terms of the same sequence. This generalizes a result by A. Fruchard and C. Zhang for Gevrey asymptotic expansions, and the proof strongly rests on a suitably refined version of the classical Phragm\'en-Lindel\"of theorem, here obtained for functions whose growth in a sector is specified by a nonzero proximate order in the sense of E. Lindel\"of and G. Valiron.Comment: 20 page

    Indices of O-regular variation for weight functions and weight sequences

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    A plethora of spaces in Functional Analysis (Braun-Meise-Taylor and Carleman ultradifferentiable and ultraholomorphic classes; Orlicz, Besov, Lipschitz, Lebesque spaces, to cite the main ones) are defined by means of a weighted structure, obtained from a weight function or sequence subject to standard conditions entailing desirable properties (algebraic closure, stability under operators, interpolation, etc.) for the corresponding spaces. The aim of this paper is to stress or reveal the true nature of these diverse conditions imposed on weights, appearing in a scattered and disconnected way in the literature: they turn out to fall into the framework of O-regular variation, and many of them are equivalent formulations of one and the same feature. Moreover, we study several indices of regularity/growth for both functions and sequences, which allow for the rephrasing of qualitative properties in terms of quantitative statements.Comment: 37 page

    The surjectivity of the Borel mapping in the mixed setting for ultradifferentiable ramification spaces

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    We consider r-ramification ultradifferentiable classes, introduced by J. Schmets and M. Valdivia in order to study the surjectivity of the Borel map, and later on also exploited by the authors in the ultraholomorphic context. We characterize quasianalyticity in such classes, extend the results of Schmets and Valdivia about the image of the Borel map in a mixed ultradifferentiable setting, and obtain a version of the Whitney extension theorem in this framework.Comment: 31 pages; this version has been accepted for publication in Monatsh. Mat

    Global and cocycle attractors for non-autonomous reaction-diffusion equations. The case of null upper Lyapunov exponent

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    In this paper we obtain a detailed description of the global and cocycle attractors for the skew-product semiflows induced by the mild solutions of a family of scalar linear-dissipative parabolic problems over a minimal and uniquely ergodic flow. We consider the case of null upper Lyapunov exponent for the linear part of the problem. Then, basically two different types of attractors can appear, depending on whether the linear coefficient in the equations determines a bounded or an unbounded associated real cocycle. In the first case (the one for periodic equations), the structure of the attractor is simple, whereas in the second case (which happens in aperiodic equations), the attractor is a pinched set with a complicated structure. We describe situations in which the attractor is chaotic in measure in the sense of Li-Yorke. Besides, we obtain a non-autonomous discontinuous pitchfork bifurcation scenario for concave equations, applicable for instance to a linear-dissipative version of the Chafee-Infante equation.Ministerio de EconomĂ­a y CompetitividadFondo Europeo de Desarrollo RegionalEuropean CommissionJunta de AndalucĂ­

    Transition to a bioeconomy: Perspectives from social sciences

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    More than 50 countries and international organisations worldwide are currently working on strategies and policies to promote a transition to a bioeconomy. This economic system centres on a sustainable use of bio- and renewable resources to guarantee sustainability. Although many contributions have been made to the field of bioeconomy, most focus on a science perspective (e.g. chemistry, engineering, technology, biomedicine or biology). Despite the significant importance of social and economic issues for a bioeconomy transition, studies from a social science perspective are largely lacking. This paper presents a systematic review of academic contributions to the field of bioeconomy from a social science standpoint. The results reveal the need for an in-depth analysis of the challenges and opportunities that the bioeconomy faces in social and economic terms
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