The search for spinning black hole binaries in mock LISA data using a genetic algorithm

Coalescing massive Black Hole binaries are the strongest and probably the most important gravitational wave sources in the LISA band. The spin and orbital precessions bring complexity in the waveform and make the likelihood surface richer in structure as compared to the non-spinning case. We introduce an extended multimodal genetic algorithm which utilizes the properties of the signal and the detector response function to analyze the data from the third round of mock LISA data challenge (MLDC 3.2). The performance of this method is comparable, if not better, to already existing algorithms. We have found all five sources present in MLDC 3.2 and recovered the coalescence time, chirp mass, mass ratio and sky location with reasonable accuracy. As for the orbital angular momentum and two spins of the Black Holes, we have found a large number of widely separated modes in the parameter space with similar maximum likelihood values.Comment: 25 pages, 9 figure

La méthode des itinéraires ou la mémoire involontaire

National audienceLa méthode des itinéraires cherche à retrouver une parole qui interroge la réalité de l'interviewé et qui fait lieu par sa concentration émotionnelle. Une parole qui en surgissant interroge la logique du sens et en propose une nouvelle interprétation et construction. Une parole qui donne une nouvelle visibilité au territoire

Spectral efficiency of engineered thermal cloaks in the frequency regime

We analyse basic thermal cloaks designed via different geometric transforms applied to thermal cloaking. We evaluate quantitatively the efficiency of these heterogeneous anisotropic thermal cloaks through the calculation of the standard deviation of the isotherms. The study addresses the frequency regime and we point out the cloak's spectral efficiencies. We find that all these cloaks have comparable efficiency irrespective of whether or not they have singular conductivity at their inner boundary. However, approximate cloaking with multi-layered cloak critically depends upon the homogenization algorithm and a large number of thin layers (at least fifty) is required to reduce substantially the standard deviation of the isotherms.Comment: 13 pages, 7 figures. The results from this article will be presented on a poster at the Metamaterials 2014 Copenhague conferenc

A pairwise likelihood approach for the empirical estimation of the underlyingvariograms in the plurigaussian models

The plurigaussian model is particularly suited to describe categorical regionalized variables. Starting from a simple principle, the thresh-olding of one or several Gaussian random fields (GRFs) to obtain categories, the plurigaussian model is well adapted for a wide range ofsituations. By acting on the form of the thresholding rule and/or the threshold values (which can vary along space) and the variograms ofthe underlying GRFs, one can generate many spatial configurations for the categorical variables. One difficulty is to choose variogrammodel for the underlying GRFs. Indeed, these latter are hidden by the truncation and we only observe the simple and cross-variogramsof the category indicators. In this paper, we propose a semiparametric method based on the pairwise likelihood to estimate the empiricalvariogram of the GRFs. It provides an exploratory tool in order to choose a suitable model for each GRF and later to estimate its param-eters. We illustrate the efficiency of the method with a Monte-Carlo simulation study .The method presented in this paper is implemented in the R packageRGeostats.Comment: To be submitted to Spatial Statistic

The search for black hole binaries using a genetic algorithm

In this work we use genetic algorithm to search for the gravitational wave signal from the inspiralling massive Black Hole binaries in the simulated LISA data. We consider a single signal in the Gaussian instrumental noise. This is a first step in preparation for analysis of the third round of the mock LISA data challenge. We have extended a genetic algorithm utilizing the properties of the signal and the detector response function. The performance of this method is comparable, if not better, to already existing algorithms.Comment: 11 pages, 4 figures, proceeding for GWDAW13 (Puerto Rico

LISACode : A scientific simulator of LISA

A new LISA simulator (LISACode) is presented. Its ambition is to achieve a new degree of sophistication allowing to map, as closely as possible, the impact of the different sub-systems on the measurements. LISACode is not a detailed simulator at the engineering level but rather a tool whose purpose is to bridge the gap between the basic principles of LISA and a future, sophisticated end-to-end simulator. This is achieved by introducing, in a realistic manner, most of the ingredients that will influence LISA's sensitivity as well as the application of TDI combinations. Many user-defined parameters allow the code to study different configurations of LISA thus helping to finalize the definition of the detector. Another important use of LISACode is in generating time series for data analysis developments

Guillaume LÉVÊQUE, Emmanuel DION et Sébastien JAHAN, Grands notables du Premier Empire. Vienne, Paris, CNRS éditions, 2000, 278 p.

Saluons dans ce volume la poursuite de l’œuvre engagée par Louis Bergeron et Guy Chaussinand-Nogaret dans le but de livrer une prosopographie complète des grands notables de l’Empire. Avec ce 26e volume coordonné par Guillaume Lévêque, le département de la Vienne vient livrer de nouvelles précisions sur le monde des élites impériales. Sont ici présentés 120 notables, sélectionnés par la synthèse de trois listes de notabilités élaborées en 1805 pour l’une, et en 1813 pour les deux autres : en ..

Homogamie et conflits dans la noblesse d'Empire, ou les fragilités d'une aristocratie moderne

Les conflits matrimoniaux ont jusqu'alors été peu étudiés par les historiens. Ils sont pourtant de précieux révélateurs d'identité et de position des protagonistes dans la société de leur temps. En offrant quelques exemples de conflits dans le cadre d'alliances homogames, les archives de la noblesse d'Empire permettent d'étudier les voies d'affirmation, mais aussi de contestation, de l'identité noble, elles éclairent les processus qui ont conduit à l'échec partiel de cette création nobiliaire de Napoléon Ier, elles renseignent sur les modalités de respect ou de rejet des bienséances matrimoniales.The historians don't often study the matrimonials conflicts. However, they revael the identities and the place of the protagonists in the society. The archives of the First Empire nobility give some examples of conflicts which show the way to assert, but also to dispute, the noble identity. They allow to understand how this institution has been a partial setback. Finally, they show how the matrimonials proprieties can be respected or refused