Change of measure in the lookdown particle system

We perform various changes of measure in the lookdown particle system of Donnelly and Kurtz. The first example is a product type h-transform related to conditioning a Generalized Fleming Viot process without mutation on coexistence of some genetic types in remote time. We give a pathwise construction of this h-transform by just "forgetting" some reproduction events in the lookdown particle system. We also provide an intertwining relationship for the Wright Fisher diffusion and explicit the associated pathwise decomposition. The second example, called the linear or additive h-transform, concerns a wider class of measure valued processes with spatial motion. Applications include: -a simple description of the additive h-transform of the Generalized Fleming Viot process, which confirms a suggestion of Overbeck for the usual Fleming Viot process -an immortal particle representation for the additive h-transform of the Dawson Watanabe process.Comment: 24 page

Stable continuous branching processes with immigration and Beta-Fleming-Viot processes with immigration

21 pagesInternational audienceBranching processes and Fleming-Viot processes are two main models in stochastic population theory. Incorporating an immigration in both models, we generalize the results of Shiga (1990) and Birkner et al. (2005) which respectively connect the Feller diffusion with the classical Fleming-Viot process and the alpha-stable continuous state branching process with the Beta(2-alpha, alpha)-generalized Fleming-Viot process. In a recent work, a new class of probability-measure valued processes, called M-generalized Fleming-Viot processes with immigration, has been set up in duality with the so-called M-coalescents. The purpose of this article is to investigate the links between this new class of processes and the continuous-state branching processes with immigration. In the specific case of the $\alpha$-stable branching process conditioned to be never extinct, we get that its genealogy is given, up to a random time change, by a Beta(2-alpha, alpha-1)-coalescent

A Williams decomposition for spatially dependent superprocesses

43 pagesInternational audienceWe present a genealogy for superprocesses with a non-homogeneous quadratic branching mechanism, relying on a weighted version of the superprocess and a Girsanov theorem. We then decompose this genealogy with respect to the last individual alive (William's decomposition). Letting the extinction time tend to infinity, we get the Q-process by looking at the superprocess from the root, and define another process by looking from the top. Examples including the multitype Feller diff usion and the superdiffusion are provided

La presse en bibliothèque

L\u27association des bibliothécaires de France (ABF) a produit un support de formation en 2021 sur les pratiques de lecture et les usages de la presse. L\u27aménagement des espaces est également abordé. Ce document de l\u27ABF, rédigé par Charlotte Hénard, fait le point en 2021 sur cette thématique

La Galería de las Máquinas de 1889. Reflexiones históricoestructurales

[EN] The Galerie des Machines of 1889 is present in most books on the history of architecture. There are, however, certain aspects of this building that merit a more in-depth study. Other elements have been incorrectly described in current and contemporary publications about the building. The aim of this article is to examine the place this building occupies in the historical development of metal arch structures, its precedents and the influence it has exerted on later buildings of a similar structure. On the other hand, there have also been contradictions concerning the materials used in the erection of the structure and the reasons behind using them, as well as the exact span achieved. This article will unequivocally resolve these issues.[ES] La Galería de las Máquinas de 1889 se encuentra presente en la mayoría de manuales de la historia de la arquitectura. Sin embargo, existen aspectos de este edificio que merecen una mayor profundización. Otros han sido objeto de incorrecciones en publicaciones actuales y contemporáneas al edificio. El presente artículo aborda cuál es el lugar que ocupa el edificio dentro del desarrollo histórico de la tipología estructural de arco metálico, cuáles han sido sus antecedentes y cuál ha sido la influencia que ha tenido en edificaciones posteriores resueltas con la misma tipología estructural. Por otra parte, los materiales utilizados en la construcción de su estructura, las razones de su utilización, así como la luz exacta que alcanzó han sido objeto de contradicciones. El artículo determina inequívocamente estos aspectos.Estévez Cimadevila, J.; López César, I. (2015). The Palais des Machines of 1889. Historical-structural Reflections. VLC arquitectura. Research Journal. 2(2):1-30. doi:10.4995/vlc.2015.3598.SWORD13022BANHAM, Reyner. Theory and design in the First Machine Age. London: The Architectural Press, 1960.Barrault, A. La charpente en fer du Palais de l'Industrie. In: Nouvelles Annales de la Construcción. February 1856.Barrault, A, Bridel, G. Le Palais de l'Industrie et ses anexes. Description raisonnée du système de construction. Paris, 1857.BENÉVOLO, Leonardo. Historia de la Arquitectura Moderna. Barcelona: Gustavo Gili, 1996.BURNHAM, Daniel H. The final official report of the director of works of the World's Columbian Exposition. Reprinted, 8 volumes, New York: Garland Publishing, Inc., 1989.Eiffel, M.M, Contamin, M. V. Discours pronouncés par M.G. Eiffel et M.V. Contamin. In: Mémoires de la Société des Ingénieurs Civils. Paris, 1890.Eiffel, M.M., CONTAMIN, FOUQUET. Note sur les constructions métalliques. In: Exposition Universelle de 1889. Congrès international des Procédés de Construction. Paris: Imprimerie et Librairie Centrales des Chemins de Fer, 1889.FERNANDEZ Troyano, Leonardo. Tierra sobre el agua: visión histórica universal de los puentes. Madrid: Colegio de Ingenieros de Caminos, Canales y Puentes, 1999.FRAMPTON, Kenneth. Studies in tectonic culture: the poetics of construction in Nineteenth and Twentith Century Architecture. Chicago: Graham Foundation for Advanced Studies in the Fine Arts, 1995.GIEDION, Sigfried. Building in France, Building in Iron, Building in Ferroconcrete. Santa Monica: The Getty Center for the History of Art and the Humanities, 1995.GIEDION, Sigfried. Espacio, Tiempo y Arquitectura. Barcelona: Reverté, 2009.GÖSSEL, Peter. Arquitectura del Siglo XX. Volume 1. Köln: Taschen, 2005.Hénard, E. Exposition Universelle de 1889: Le Palais des Machines, Notice sur l'édifice et sur la Marche des Travaux. Paris: Librairies Imprimeries Réunies, 1891.Hénard, E. Les travaux de l'Exposition. Le montage des grandes fermes du Palais des Machines. In: Le Genie Civil. Revue générale des Industries Françaises & Étrangères. September 1888.LEMOINE, Bertrand. Eiffel. Barcelona: Stylos, 1986.LOYER, François. Le siècle de l'industrie: 1789-1914. Paris: Skira, 1983.MALLET, Robert. Record of the International Exhibition London 1851. Glasgow: William Mackenzie, 1862.MEEKS, Carroll L.V. The Railroad Station: an Architectural History. 2Nd reprinting, London: Yale University Press, 1956.PEVSNER, Nikolaus. Los orígenes de la arquitectura moderna y del dise-o. Barcelona: Gustavo Gili, 1973.Picon, A. L'art de l'ingenieur. Paris: Éditions du Centre Pompidou, 1997.VIERENDEEL, Arthur. La Construction Architecturale en Fonte, Fer et Acier. 2 Volumes. Brussels: Dunod, 1902.WATSON, William. Paris Universal Exposition 1889: Civil Engineering, Public Works and Architecture. Washington: Washington Government Printing Office, 1892

The local limit of rooted directed animals on the square lattice

We consider the local limit of finite uniformly distributed directed animals on the square lattice viewed from the root. Two constructions of the resulting uniform infinite directed animal are given: one as a heap of dominoes, constructed by letting gravity act on a right-continuous random walk and one as a Markov process, obtained by slicing the animal horizontally. We look at geometric properties of this local limit and prove, in particular, that it consists of a single vertex at infinitely many (random) levels. Several martingales are found in connection with the confinement of the infinite directed animal on the non-negative coordinates.Comment: 59 pages, 16 figure