En route pour le centenaire

Henri Michel fut l\u27un des fondateurs de l’ABF, qu’il présida pendant la Première Guerre mondiale. Moins utopiste qu’Eugène Morel, il fut aussi plus politique, et soutint l’idée d’adjoindre les « populaires » aux municipales. De son long plaidoyer en faveur de la valeur patrimoniale de ces dernières1, nous ne retenons ici que quelques passages, teintés d’humour et de poésie. Qualités qui leur valent d’être souvent cités… Mais tout le texte est, pour ses contemporains, une invite à l’action en faveur de la bibliothèque

Non-exponential spontaneous emission dynamics for emitters in a time-dependent optical cavity

We have theoretically studied the effect of deterministic temporal control of spontaneous emission in a dynamic optical microcavity. We propose a new paradigm in light emission: we envision an ensemble of two-level emitters in an environment where the local density of optical states is modified on a time scale shorter than the decay time. A rate equation model is developed for the excited state population of two-level emitters in a time-dependent environment in the weak coupling regime in quantum electrodynamics. As a realistic experimental system, we consider emitters in a semiconductor microcavity that is switched by free-carrier excitation. We demonstrate that a short temporal increase of the radiative decay rate depletes the excited state and drastically increases the emission intensity during the switch time. The resulting time-dependent spontaneous emission shows a distribution of photon arrival times that strongly deviates from the usual exponential decay: A deterministic burst of photons is spontaneously emitted during the switch event.Comment: 12 pages, 4 figure

For Jean-Pierre Chauveau: A Personal Take, by Henri-Michel Yéré

The history of anthropology constituted itself at the interface of changing contexts, persons (academic and non-academic anthropologists) and institutions (research organizations, funding agencies, political and bureaucratic authorities). The recent publication of a Festschrift for Jean-Pierre Chauveau1 and the panel we organized around the book for the ECAS conference in Lisbon, June 2013, provided two ideal occasions for an in-depth discussion on these complex linkages. The long run of this articulation of the country’s history, the institutional commitment of ORSTOM/IRD and the personal involvement of Jean-Pierre Chauveau has allowed the latter to study in depth a wide range of topics, with ever more inspiration, thus building an ‘anthropology between power and history’ (the title of the Festschrift, published at the end of 2011, to honour his work). His deep involvement permitted Chauveau to bring out the interconnection between the region’s plantation economy, issues of land and migration, a longterm history of settlement and exchange, state formation, the dispositifs of development and state formation, colonial and post-colonial governmentality. The productivity of this articulation of context, researcher and institution is also borne out by the broad audience interested in this work: specialists of Ivory Coast but also colleagues and observers interested in politics and issues of development in general. Henri-Michel Yéré takes here the opportunity to pursue this conversation and links in this stimulating paper different strands of the reflection – on development, state making and belonging – by focusing on the Ivorian postcolonial trajectory and the intellectual and political debates its qualification nurtured

Contrats financiers avec asymétrie de l’information dans un cadre dynamique

Cet article présente une caractérisation des contrats financiers d’équilibre dans un modèle à deux périodes avec sélection adverse. Nous analysons le cas où l’information privée de l’entrepreneur sur la rentabilité de son projet est parfaitement corrélée sur les deux périodes. Dans ce contexte dynamique, nous démontrons que les contrats d’équilibre sont sensiblement différents de ceux dérivés dans le modèle statique.This article characterizes equilibrium financial contracts in a two-period model with adverse selection. We consider the case in which private information of the entrepreneur about the profitability of his project is perfectly corraleted across periods. We show that, in a dynamic context, equilibrium contracts may significantly differ from those of the static model

Measure of Macroeconomics of CFA Zone Countries Compare to SSA Countries

The research is financed by the school of finance and economics of Jiangsu University (+86 511 8878 0011) Abstract The influence of services activity in the economic development regarding the macroeconomics tactics and application. We investigate the sources of macroeconomics fluctuations in Sub-Saharan African (SSA) countries with particular attention to the development growth, federal investment, gross national income and consumer price with a structural Vector Auto regression (VAR) model with limited capital mobility and long run restrictions to identify the shocks.  The research data analyzed by Linear square, in the first step data has been manipulated by level of stationary in first root and then with unit root individually classify the regions distribution with each expects to estimation development and confirm that even though the development techniques by individual development of SSA. However, terms of growth intention and development tend to influence the CFA zone to a greater extent and there seems to be a higher influence of demand shocks on output and the federal investment and consumer prices in the non-CFA countries. Supply and terms of trade shocks tend to dominate output movements in the CFA and non-CFA countries alike. Keywords: Economic development; SSA and CFA; macroeconomics DOI: 10.7176/RJFA/11-4-11 Publication date: February 29th 2020

Checking for optimal solutions in some NPNP-complete problems

For some weighted $NP$-complete problems, checking whether a proposed solution is optimal is a non-trivial task. Such is the case for the celebrated traveling salesman problem, or the spin-glass problem in 3 dimensions. In this letter, we consider the weighted tripartite matching problem, a well known $NP$-complete problem. We write mean-field finite temperature equations for this model, and show that they become exact at zero temperature. As a consequence, given a possible solution, we propose an algorithm which allows to check in a polynomial time if the solution is indeed optimal. This algorithm is generalized to a class of variants of the multiple traveling salesmen problem