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The exact Wheeler-DeWitt equation for the scale-factor minisuperspace model
No full textInternational audienceWe consider the classical minisuperspace model describing a closed, homogeneous and isotropic Universe, with a positive cosmological constant. Upon canonical quantization, the infinite number of possible operator orderings in the quantum Hamiltonian leads to distinct Wheeler-DeWitt equations for the wavefunction of the Universe. Similarly, ambiguity arises in the path-integral formulation of , due to the infinite choices of path-integral measures for the single degree of freedom of the model. For each choice of path-integral measure, we determine the correct operator ordering of the quantum Hamiltonian and derive the exact form of the Wheeler-DeWitt equation, including all corrections in . Additionally, we impose Hermiticity of the Hamiltonian to deduce the Hilbert-space measure , which appears in the definition of the Hermitian inner product. Remarkably, all quantum predictions can be expressed through the combination , which satisfies a universal Wheeler-DeWitt equation, independent of the initial path-integral prescription. This result demonstrates that all seemingly distinct quantum theories arising from different quantization schemes of the same classical model are fundamentally equivalent
Appréhender la gestion de l’héritage des organisations temporaires : Le cas de l’organisation des JOP de Paris 2024
No full textInternational audienceThis article focuses on the management of the legacy of mega-events, studying the case of the Paris 2024 Olympic and Paralympic Games. It explores the complexity of this legacy, which encompasses both tangible and intangible aspects and covers multiple dimensions: cultural, economic, social and environmental. Through participant observation conducted within the Paris 2024 organization, our study examines the management mechanisms that enable the organization to shape, steer, and manage this legacy. Our findings highlight the critical role of an early shared vision, a unit dedicated to legacy development, and innovative monitoring and control devices. We also analyze two flagship programs, Terre de Jeux 2024 and Club Paris 2024, which are detailed to illustrate the intangible dimension of the legacy and the role of communities in its transmission. Finally, we discuss the perspectives and limitations of legacy governance and management in temporary organizationsCet article met l'accent sur la gestion de l'héritage des méga-événements, en se penchant particulièrement sur les Jeux olympiques et paralympiques de Paris 2024. Il explore la complexité de cet héritage, englobant des aspects matériels et immatériels, et intégrant de nombreuses dimensions : culturelle, économique, sociale, environnementale. À travers une observation participante menée au sein de l’organisation des jeux, Paris 2024, notre étude se concentre sur les dispositifs permettant à l’organisation d’assurer un pilotage et une gouvernance de l’héritage. Nos résultats montrent qu’une planification précoce et une vision partagée, une unité dédiée et des mécanismes novateurs de suivi et de contrôle de l’héritage ont joué un rôle majeur. Nous analysons aussi deux programmes phares, Terre de Jeux 2024 et Club Paris 2024, qui sont présentés pour illustrer la dimension immatérielle de l'héritage, et sa transmission à travers des communautés d’apprentissage. En conclusion, nous discutons des perspectives et des limites des dispositifs de gestion de l'héritage pour les organisations temporaires
Renault-Nissan as a Project of Projects: A Relational Approach to Strategic Alliances
No full textInternational audienceThe study of strategic alliances has traditionally focused on their initial purpose and examined the complementarities in assets and competences that prompt two firms with aligned objectives to collaborate. More recently, research has shifted toward understanding the dynamic nature of these alliances. In alignment with Dyer and his colleagues (1998; 2018), this article seeks to investigate the Renault-Nissan strategic alliance as a relationship conceptualized as a project of projects. To achieve this, this study draws on the literature on alliances, relationships, and projects. Through the analysis of the Renault-Nissan Alliance, the study establishes that this collaboration is a dynamic, multilevel relationship that articulates an unfinished project (‘unfinished business’; Duck, 1990) and finished projects and that presents itself as a project of projects. Within this dynamic framework, the future takes precedence over the past (questioning the importance of relational capital). By examining the Renault-Nissan case through the lens of relational dynamics as a project of projects, this article makes thoughtful contributions to the theories of alliances, projects, and relationships.Les alliances stratégiques ont surtout été étudiées sous l’angle de leur raison d’être ex ante, c’est-à-dire les complémentarités des avoirs et des compétences incitant deux firmes ayant le même objectif à coopérer. Plus récemment, des études se sont intéressées à l’aspect dynamique des alliances. Dans la ligne de Dyer et ses collègues (1998 ; 2018), l’article se propose d’étudier l’alliance stratégique Renault-Nissan comme une relation conçue comme un projet. Pour ce faire, il mobilise la littérature sur les alliances, celle sur les relations et, enfin, celle sur les projets. Analysant le cas de l’alliance Renault-Nissan, il établit que cette alliance est une relation dynamique multiniveau qui articule un projet indéfini (unfinished business ; Duck, 1990) et des projets définis sous la forme globale d’un projet de projets. Dans cette dynamique, le futur prime sur le passé (le capital relationnel). En analysant le cas Renault-Nissan dans sa dynamique relationnelle comme un projet de projets, l’article contribue à la théorie des alliances, à celle des projets et à celle des relations
Intrinsic Interleaving Distance for Merge Trees
No full textInternational audienceMerge trees are a type of graph-based topological summary that tracks the evolution of connected components in the sublevel sets of scalar functions. They enjoy widespread applications in data analysis and scientific visualization. In this paper, we consider the problem of comparing two merge trees via the notion of interleaving distance in the metric space setting. We investigate various theoretical properties of such a metric. In particular, we show that the interleaving distance is intrinsic on the space of labeled merge trees and provide an algorithm to construct metric 1-centers for collections of labeled merge trees. We further prove that the intrinsic property of the interleaving distance also holds for the space of unlabeled merge trees. Our results are a first step toward performing statistics on graph-based topological summaries
Measurement of CP asymmetry in decays
No full textInternational audienceA measurement of the CP-violating parameters in BsDsK decays is reported, based on the analysis of proton-proton collision data corresponding to an integrated luminosity of at a centre-of-mass energy of . The measured parameters are , , , and , where the first uncertainty is statistical and the second systematic. Together with the value of the Bs mixing phase , these parameters are used to obtain a measurement of the CKM angle equal to modulo , where the uncertainty contains both statistical and systematic contributions. This result is combined with the previous LHCb measurement in this channel using resulting in a determination of
Higher derivative couplings with multi-tensor multiplets in 6D supergravity, action and anomalies
No full textInternational audienceWe revisit six-dimensional (1,0) supergravity coupled to nT tensor multiplets and Yang-Mills fields for nT>1 for which no covariant action exists. We construct the action in the Henneaux-Teitelboim approach and in the presence of a gauge anomaly. We moreover obtain the supersymmetric Green-Schwarz counterterm for the gravitational anomaly for arbitrary matter content
Quantum Gravity, Hydrodynamics and Emergent Cosmology: A Collection of Perspectives
No full textInternational audienceThis collection of perspective pieces captures recent advancements and reflections from a dynamic research community dedicated to bridging quantum gravity, hydrodynamics, and emergent cosmology. It explores four key research areas: (a) the interplay between hydrodynamics and cosmology, including analog gravity systems; (b) phase transitions, continuum limits and emergent geometry in quantum gravity; (c) relational perspectives in gravity and quantum gravity; and (d) the emergence of cosmological models rooted in quantum gravity frameworks. Each contribution presents the distinct perspectives of its respective authors. Additionally, the introduction by the editors proposes an integrative view, suggesting how these thematic units could serve as foundational pillars for a novel theoretical cosmology framework termed "hydrodynamics on superspace"
Les ébauches zoliennes pour enseigner la langue et la culture à des étudiants internationaux
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Search for the Higgs boson decays to a , , or K meson and a photon in proton-proton collisions at = 13 TeV
No full textInternational audienceThree rare decay processes of the Higgs boson to a (770), (1020), or K(892) meson and a photon are searched for using = 13 TeV proton-proton collision data collected by the CMS experiment at the LHC. Events are selected assuming the mesons decay into a pair of charged pions, a pair of charged kaons, or a charged kaon and pion, respectively. Depending on the Higgs boson production mode, different triggering and reconstruction techniques are adopted. The analyzed data sets correspond to integrated luminosities up to 138 fb, depending on the reconstructed final state. After combining various data sets and categories, no significant excess above the background expectations is observed. Upper limits at 95% confidence level on the Higgs boson branching fractions into (770), (1020), and K(892) are determined to be 3.7 10, 3.0 10, and 3.0 10, respectively. In case of the (770) and (1020) channels, these are the most stringent experimental limits to date