11,030 research outputs found

    Dispersion relations for the time-fractional Cattaneo-Maxwell heat equation

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    In this paper, after a brief review of the general theory of dispersive waves in dissipative media, we present a complete discussion of the dispersion relations for both the ordinary and the time-fractional Cattaneo-Maxwell heat equations. Consequently, we provide a complete characterization of the group and phase velocities for these two cases, together with some non-trivial remarks on the nature of wave dispersion in fractional models.Comment: 18 pages, 7 figure

    Are the Elderly a Threat to Educational Expenditures?

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    Empirical research has given cause to fear that the demographic ageing in industrialized countries is likely to exert a negative impact on educational spending. These papers have linked the share of the elderly with the per capita or per pupil spending on education at the local, state-wide or national level, trying to control for other exogenous effects. Although this line of research shows in many cases a negative correlation between the shares of elderly people and educational expenditures, a causal link is difficult to prove. This paper uses a unique and representative survey of Swiss voters of all age groups. The analysis shows that elderly people present a clear tendency to be less willing to spend money on education. They would rather prefer to spend public resources on health and social security than on education. Furthermore the paper shows that much of the negative correlation between the shares of elderly and educational spending is the result of the elderly being politically more conservative and in general less inclined to pay for expenditures in the public sector as a whole.public finance, education finance, demographics, survey, Switzerland

    The Relative Space: Space Measurements on a Rotating Platform

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    We introduce here the concept of relative space, an extended 3-space which is recognized as the only space having an operational meaning in the study of the space geometry of a rotating disk. Accordingly, we illustrate how space measurements are performed in the relative space, and we show that an old-aged puzzling problem, that is the Ehrenfest's paradox, is explained in this purely relativistic context. Furthermore, we illustrate the kinematical origin of the tangential dilation which is responsible for the solution of the Ehrenfest's paradox.Comment: 14 pages, 2 EPS figures, LaTeX, to appear in the European Journal of Physic

    Non-symplectic automorphisms of odd prime order on manifolds of K3 [n] -type

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    We contribute to the classification of non-symplectic automorphisms of odd prime order on irreducible holomorphic symplectic manifolds which are deformations of Hilbert schemes of any number n of points on K3 surfaces, extending results already known for n = 2. In particular, we study the properties of the invariant lattice of the automorphism (and its orthogonal complement) inside the second cohomology lattice of the manifold. We also explain how to construct automorphisms with fixed action on cohomology: in the cases n = 3, 4 the examples provided realize all admissible actions in our classification. For n = 4, we present a construction of non-symplectic automorphisms on the Lehn\u2013Lehn\u2013Sorger\u2013van Straten eightfold, which come from automorphisms of the underlying cubic fourfold

    Flexible Conservation Measures on Working Land: What Challenges Lie Ahead?

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    From 1985 to 2002, most Federal conservation dollars going to farm operators have been to retire land from crop production. Yet most U.S. farmland (850 million acres) remains in active production. The Farm Security and Rural Investment (FSRI) Act of 2002 sharply increased conservation funding and earmarked most of the increase for working-land payment programs (WLPPs). The design and implementation of WLPPs will largely determine the extent to which environmental goals are achieved and whether they are cost effective. We simulate potential environmental gains as well as adjustments in agricultural production, price, and income associated with various WLPP features to illustrate tradeoffs arising from WLPP design and implementation. Competitive bidding with the use of environmental indices to rank producers for enrollment is most cost effective. Payments based on past conservation will help support farm incomes, but limit the amount of additional environmental benefit that can be generated under a fixed budget.Land Economics/Use,

    AKSZ-BV Formalism and Courant Algebroid-induced Topological Field Theories

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    We give a detailed exposition of the Alexandrov-Kontsevich-Schwarz- Zaboronsky superfield formalism using the language of graded manifolds. As a main illustarting example, to every Courant algebroid structure we associate canonically a three-dimensional topological sigma-model. Using the AKSZ formalism, we construct the Batalin-Vilkovisky master action for the model.Comment: 13 pages, based on lectures at Rencontres mathematiques de Glanon 200

    Classical BV theories on manifolds with boundary

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    In this paper we extend the classical BV framework to gauge theories on spacetime manifolds with boundary. In particular, we connect the BV construction in the bulk with the BFV construction on the boundary and we develop its extension to strata of higher codimension in the case of manifolds with corners. We present several examples including electrodynamics, Yang-Mills theory and topological field theories coming from the AKSZ construction, in particular, the Chern-Simons theory, the BFBF theory, and the Poisson sigma model. This paper is the first step towards developing the perturbative quantization of such theories on manifolds with boundary in a way consistent with gluing.Comment: The second version has many typos corrected, references added. Some typos are probably still there, in particular, signs in examples. In the third version more typoes are corrected and the exposition is slightly change
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