11,161 research outputs found

    Transport equation with nonlocal velocity in Wasserstein spaces: convergence of numerical schemes

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    Motivated by pedestrian modelling, we study evolution of measures in the Wasserstein space. In particular, we consider the Cauchy problem for a transport equation, where the velocity field depends on the measure itself. We deal with numerical schemes for this problem and prove convergence of a Lagrangian scheme to the solution, when the discretization parameters approach zero. We also prove convergence of an Eulerian scheme, under more strict hypotheses. Both schemes are discretizations of the push-forward formula defined by the transport equation. As a by-product, we obtain existence and uniqueness of the solution. All the results of convergence are proved with respect to the Wasserstein distance. We also show that L1L^1 spaces are not natural for such equations, since we lose uniqueness of the solution

    “Disguised in scarlet”. Hume and Turin in 17481

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    Archive Research concerning the following subjects: Hume in Turin (8 May - 29 November 1748) as secretary and aide-de-camp to General St Clair. St Clair's mission and correspondence (his letters written by Hume). Hume's account of plains and fortifications (the principle of sympathy). Hume's maladay and religion. 'Of National Characters' and Hume's reading of Montesquieu's Esprit. Hume and Lord Charlemont

    Generalized Wasserstein distance and its application to transport equations with source

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    In this article, we generalize the Wasserstein distance to measures with different masses. We study the properties of such distance. In particular, we show that it metrizes weak convergence for tight sequences. We use this generalized Wasserstein distance to study a transport equation with source, in which both the vector field and the source depend on the measure itself. We prove existence and uniqueness of the solution to the Cauchy problem when the vector field and the source are Lipschitzian with respect to the generalized Wasserstein distance

    Modeling self-organization in pedestrians and animal groups from macroscopic and microscopic viewpoints

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    This paper is concerned with mathematical modeling of intelligent systems, such as human crowds and animal groups. In particular, the focus is on the emergence of different self-organized patterns from non-locality and anisotropy of the interactions among individuals. A mathematical technique by time-evolving measures is introduced to deal with both macroscopic and microscopic scales within a unified modeling framework. Then self-organization issues are investigated and numerically reproduced at the proper scale, according to the kind of agents under consideration.Comment: 24 pages, 13 figure
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