HAL Université de Savoie
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Bethe Vectors in Quantum Integrable Models with Classical Symmetries
No full textInternational audienceThe first goal of this paper is to give a precise and simple definition for off-shell Bethe vectors in a generic -invariant integrable model for , , and . We prove from our definition that the off-shell Bethe vectors indeed become on-shell when the Bethe equations are obeyed. Then, we show that some properties for these off-shell Bethe vectors, such as the action formulas of monodromy entries on these vectors, their rectangular recurrence relations and their coproduct formula, are a consequence of our definition
Thermal coupling between a Small Modular Nuclear Reactor and a High-Temperature Steam Electrolysis process: Energy performance mapping of key design options
No full textInternational audienceThis article presents the main results of a three-year R&D program on the coupling of a Small Modular Reactor(SMR) nuclear unit to a hydrogen production process using High-Temperature Steam Electrolysis (HTSE).Different coupling architectures are investigated and their energetic evaluation is performed in comparison witha reference configuration. The separate effects that are considered are comprehensive and include: thermalcoupling (with or without, unidirectional or bidirectional − modulo internal heat recovery effort in the HTSEprocess itself), direct or indirect steam supply, location of the Rankine cycle extraction point, pressurization ofthe HTSE (with or without mechanical energy recovery through gas expansion) and oxygen content (impact ofthe swept gas). Remarkably, the simulation results obtained on the reference configuration show a gain of over13% in hydrogen production compared with the solution involving no thermal coupling between the SMR andthe HTSE process (when HTSE heat is provided through electrical heaters), with a deviation as low as 3 % froman idealized configuration with freely available heat. It even outperforms the heat-pump solution by more than 4%. These key energetic results were supplemented by other technical criteria, such as those relating to safety andtechnological maturity
Complete computation of all three-loop five-point massless planar integrals
No full textInternational audienceWe calculate all three-loop, five-point, massless planar Feynman integral families in the dimensional regularization scheme. This is a new milestone in Feynman integral computations. The analysis covers four distinct families of Feynman integrals for this configuration, for all of which we derive the canonical differential equations. Our results also confirm a prediction on the three-loop five-point alphabet. The boundary values are analytically determined. Using these differential equations, the integrals can be evaluated to high precision efficiently. Our work establishes the foundation for next-to-next-to-next-to-leading-order (NLO) calculation of the production of three massless final states, as well as corresponding bootstrap studies in gauge theories
Le cri de Blessing Matthew : enquête sur les morts des frontières
No full textvisionscarto.net, https://www.visionscarto.net/le-cri-de-blessing-matthew-enqueteBlessing Matthew venait de franchir la frontière italo-française. Le 7 mai 2018, en tombant dans la Durance, elle aurait hurlé trois fois « Help me ! » sans que les forces de l’ordre présentes sur place ne lui portent secours. Sa sœur nous a confié que Blessing « continuera de hurler » tant que justice ne sera pas faite. La frontière, ce matin-là, a crié. Un collectif de chercheur·es et de militant·es a « entendu » son cri et conduit une contre-enquête pour reconstituer les événements qui ont mené à sa mort. Les preuves collectées montrent que la jeune femme n’est pas décédée par accident, ni du fait de la montagne ou de la rivière. Sa mort s’ancre dans un contexte de politiques migratoires restrictives, qui cible certaines catégories de la population et transforme l’environnement alpin en arme létale
Search for ttbar resonances in final states with exactly one or two leptons using 140 fb of pp collision data at TeV with the ATLAS experiment
No full textInternational audienceA search for heavy spin-1 and spin-2 resonances decaying into a top-antitop-quark pair has been performed with 140 fb of proton-proton collision data collected by the ATLAS experiment at the Large Hadron Collider at a centre-of-mass energy of TeV. Final states with either exactly one electron or muon, or exactly two leptons (, or ), large missing transverse momentum, and two jets, at least one of which must be identified as likely containing a b-hadron decay, are considered. The search targets resonances with both narrow and broad widths relative to the detector resolution, and with masses in the range of 0.4-5.0 TeV. No significant deviation from the Standard Model prediction is observed. Exclusion limits are set on the production cross-section times branching ratio for hypothetical bosons, Kaluza-Klein gravitons, and Kaluza-Klein gluons that decay into top-quark pairs
Kination and the Inert Doublet Model
No full textInternational audienceThe inert doublet model is a two-Higgs-doublet extension of the standard model that provides a minimal and versatile framework for frozen-out dark matter. Assuming standard cosmology, if the dark matter mass ranges between approximately 120 GeV and 500 GeV then it turns out to be underabundant, as gauge interactions render its annihilation too efficient. In this work, we show that this mass window becomes allowed in cosmological scenarios where dark matter freeze-out occurs during a period with a stiff equation of state, w > 1/3, such as kination. This predictive setup satisfies all current experimental constraints while remaining within the reach of upcoming detection efforts
Flood pulse monitoring in wetlands with multi-temporal Sentinel-1 interferometric coherence data: Application to the Okavango Delta (Botswana)
No full textInternational audienceFlood-pulsed wetlands are characterized by significant seasonal water fluctuations, which play a critical role in the dynamics of these sensitive ecosystems. Among the growing number of existing remote sensing products, we explore the potential of interferometric (InSAR) coherence time series, derived from Sentinel-1 synthetic-aperture radar images, to characterize the hydrological dynamics of the Okavango Delta, a vast flood-pulsed wetland. Interferometric coherence reflects changes in surface conditions, making it a powerful tool for detecting flood propagation. By fitting harmonic functions, we produce parameters that quantify the seasonality of coherence time series with short isotemporal baselines (12 days). In particular, we developed a normalized seasonal index based on the ratio between the seasonal amplitude and the root-mean-square error of the fitted harmonic function, to map the seasonality of the coherence time series. A multi-annual analysis of coherence time series reveals a strong relationship between their seasonality, land cover, and flood frequency. Unsupervised clustering applied to statistical and seasonal metrics of coherence time series yields consistent classifications that map the variability of flood frequencies across wetland areas and clearly distinguish wetlands from dry zones. Similarly thresholds applied to normalized seasonal indices delineate the year-to-year extent of flood pulses with accuracy around 79 %. We show that coherence time series in never flooded areas exhibit a pronounced seasonal pattern driven by rainfall cycle, whereas this seasonality is disrupted by flood pulses in wetlands. Building on this, developed a change-detection approach to map the floods by identifying the date when coherence time series diverge from their seasonal pattern. The resulting flood arrival dates achieve 74–83 % accuracy compared to a reference dataset derived from optical data. Our results highlight the potential of coherence time series as a robust indicator of seasonal variations in inundation extent in flood-pulsed wetlands
Patellofemoral alignment safe zones in robotic‐assisted TKA do not affect outcomes but do influence patellar resurfacing rates
No full textInternational audienceAbstract Purpose Anterior compartment management remains a challenging aspect of total knee arthroplasty (TKA), particularly in personalised alignment strategies. This study aimed to assess whether restoring patellofemoral alignment parameters within predefined safe zones—specifically patellar tilt (PTi), patellar translation (PTr) and patellar offset (PO)—is associated with improved clinical outcomes following robotic‐assisted TKA (rTKA). Methods This retrospective study included 283 patients who underwent primary rTKA between March 2021 and January 2023 using functional alignment (FA) or functional knee positioning (FKP) principles. All surgeries were performed using a CT‐based robotic system (Mako, Stryker). Patients were stratified into groups based on radiographic values of PTi, PTr and ΔPO, using thresholds derived from prior robotic studies to define safe zones. Clinical outcomes at a mean follow‐up of 2.8 ± 0.8 years included Knee Society Score (KSS), Forgotten Joint Score‐12 (FJS‐12) and Kujala Anterior Knee Pain Scale (AKPS). Results There were no statistically significant differences in final KSS, FJS‐12 or AKPS between groups within or outside the safe zones for PTi, PTr or ΔPO. However, patients with PTi < 0°, ΔPO > 0 mm (overstuffing) or PTr within ±2 mm showed significantly higher rates of patellar resurfacing ( p < 0.001). No group demonstrated superior clinical outcomes across the three parameters studied. Conclusion Restoring patellofemoral alignment parameters within predefined safe zones was not associated with improved short‐term clinical outcomes in rTKA. Robotic‐assisted FA provides accurate restoration of the anterior compartment, reducing reliance on patellar resurfacing in eligible patients. Our data suggest that target biomechanical parameters can potentially be achieved without resurfacing in cases where it is not indicated. Our hypothesis that patients within the proposed safe zones would demonstrate improved clinical outcomes was not supported by the current results. Further prospective studies are needed to determine whether femoral safe zones can predict long‐term benefit. Level of Evidence Level II
Identification of transdiagnostic phenomena among patients, the general population, relatives, and mental health professionals using topic modeling techniques
No full textInternational audienceIntroduction Recent research has highlighted the limitations of the categorical approach to mental disorders and has increasingly supported the development of a transdiagnostic perspective. This emerging approach focuses on common distal factors (circumstantial, biological, and social) and psychological processes that contribute to psychological suffering across a range of disorders, as well as on the resulting psychological symptoms. The present study aims to identify transdiagnostic distal factors, psychological processes, and symptoms by analyzing narratives through topic modeling—an unsupervised machine learning technique, specifically within Natural Language Processing (NLP). Topic modeling enables the automatic extraction of latent themes from unstructured text, making it possible to identify psychological patterns grounded in patients’ lived experiences. Methods We recruited four groups of participants: Patients diagnosed with a psychiatric disorder ( N = 445), Individuals from the general population ( N = 570), Relatives of patients with psychiatric disorders ( N = 354), and Mental health professionals ( N = 131). Participants answered open-ended questions exploring the causes of psychological suffering, their wishes for change, and their previous experiences with psychotherapy. Results We identified 258 topics, which were organized into 12 overarching themes. The most prominent topics concerned Emotional and Psychological Difficulties , Family and Social Relationships , and Therapeutic Processes . Each theme showed a comparable prevalence across the different diagnostic categories, supporting the transdiagnostic nature of these phenomena. Conclusion Topic modeling can be used effectively to identify transdiagnostic distal factors, psychological processes, and symptoms from diverse narratives. This approach tends to provide a novel means of supporting the relevance and validity of the transdiagnostic perspective
"L’illusion du mauvais choix : coûts d’opportunité et croyance dans la redondance des agents immobiliers"
No full textInternational audiencePurpose This paper examines how digital disintermediation and perceptions of broker usefulness influence homebuyers’ satisfaction in real estate transactions. It introduces the concept of broker redundancy beliefs (BRB) to understand the psychological impact of opportunity costs when buyers choose to work with a broker instead of pursuing a direct transaction (FSBO). Design/methodology/approach A survey of 1,964 French homebuyers was conducted to compare outcomes between brokered and direct transactions. Using moderated mediation models, the study assesses how transaction type influences price satisfaction and recommendation intentions, and how these effects are conditioned by BRB. Findings Results show that buyers using brokers report significantly lower price satisfaction and are less likely to recommend this transaction mode, despite similar purchase prices and shorter search durations. The negative impact is entirely moderated by BRB: when BRB is low, the effect disappears. These results suggest that the perception of opportunity cost—rather than actual outcomes—drives dissatisfaction. Research limitations/implications This study highlights how opportunity cost perceptions and broker redundancy beliefs shape buyer satisfaction, offering a behavioral explanation for persistent skepticism toward brokers. Although based on French data, the mechanisms identified are relevant across markets where digital platforms increase the visibility of FSBO alternatives. The findings imply that brokers must actively demonstrate skills, effort, and ethical conduct to counter redundancy perceptions, while policymakers and platform designers should consider how intermediation is positioned in increasingly digital ecosystems. Limitations such as data timing, response rate uncertainty, and lack of seller perspectives point to fruitful avenues for future research. Practical implications In an AI-enhanced real estate environment, brokers must visibly demonstrate skill and effort to counteract perceptions of redundancy. Younger, digital-native buyers with high BRB represent a critical target for repositioning brokerage value. Emphasizing ethical conduct, transparency, and personalized insight may help rebuild trust. Social implications This research shows that buyer dissatisfaction with brokers is not purely economic but rooted in perceived opportunity costs and redundancy beliefs. Such perceptions may erode trust in professional intermediation and accelerate a shift toward peer-to-peer transactions, reinforcing broader patterns of digital disintermediation in society. The findings highlight the importance of transparency, ethical conduct, and visible value creation in maintaining consumer confidence in intermediaries. They also suggest that without renewed credibility, brokerage risks losing its social legitimacy, particularly among younger and more digitally literate generations, with potential consequences for fairness, accountability, and professionalism in housing markets. Originality/value This study provides a novel psychological explanation for declining buyer satisfaction in brokered transactions, despite equivalent outcomes. It highlights how perceived opportunity cost and cognitive bias influence evaluations of intermediation in real estate.ObjectifCette étude étudie comment la désintermédiation numérique et les perceptions de l’utilité des agents immobiliers influencent la satisfaction des acheteurs dans les transactions immobilières. Elle introduit le concept de croyances en la redondance des agents (CRA) pour analyser l’impact psychologique des coûts d’opportunité lorsque les acheteurs choisissent de recourir à un agent plutôt qu’à une transaction directe (vente entre particuliers, ou FSBO). Le cadre théorique s’appuie sur l’idée que ces croyances modulent la satisfaction perçue, indépendamment des résultats objectifs.MéthodologieUne enquête a été menée auprès de 1 964 acheteurs français pour comparer les résultats des transactions réalisées avec ou sans agent. À l’aide de modèles de médiation modérée, l’étude évalue comment le type de transaction affecte la satisfaction concernant le prix et l’intention de recommander ce mode de transaction, ainsi que le rôle des CRA dans ces relations.RésultatsLes résultats révèlent que les acheteurs ayant utilisé un agent déclarent une satisfaction significativement plus faible concernant le prix et sont moins enclins à recommander ce mode de transaction, malgré des prix d’achat similaires et des durées de recherche plus courtes. Cet effet négatif est entièrement modéré par les croyances CRA : lorsque celles-ci sont faibles, cet impact négatif disparaît. Ces résultats suggèrent que la perception de coûts d’opportunité, plutôt que les résultats effectifs, est le principal moteur de l’insatisfaction.Limites et implications pour la rechercheCette étude met en lumière comment les perceptions des coûts d’opportunité et les croyances en la redondance des agents façonnent la satisfaction des acheteurs, offrant une explication comportementale à la persistance de la méfiance envers les professionnels de l'immobilier. Les mécanismes identifiés sont pertinents pour comprendre les marchés où les plateformes numériques augmentent la visibilité des alternatives FSBO. Les résultats impliquent que les agents doivent démontrer activement leurs compétences, leurs efforts et leur éthique pour contrer les perceptions de redondance. Les limites, telles que le timing des données, l’incertitude sur le taux de réponse et l’absence de perspective des vendeurs, ouvrent des pistes pour de futures recherches.Implications pratiquesDans un environnement immobilier enrichi par l’IA, les agents doivent rendre visibles leurs compétences et leurs efforts pour contrer les perceptions de redondance. Les acheteurs plus jeunes, natifs du numérique et présentant des CRA élevées, constituent une cible critique pour repositionner la valeur du courtage. Mettre l’accent sur l’éthique, la transparence et des conseils personnalisés pourrait contribuer à rétablir la confiance.Implications socialesCette recherche montre que l’insatisfaction des acheteurs envers les agents n’est pas purement économique, mais ancrée dans les perceptions des coûts d’opportunité et des croyances en la redondance. Ces perceptions pourraient éroder la confiance dans l’intermédiation professionnelle et accélérer le passage vers des transactions de pair à pair, renforçant ainsi les tendances plus larges de désintermédiation numérique dans la société. Les résultats soulignent l’importance de la transparence, de l’éthique et de la création de valeur visible pour maintenir la confiance des consommateurs dans les intermédiaires. Sans une crédibilité renouvelée, le courtage risque de perdre sa légitimité sociale, en particulier auprès des générations plus jeunes et plus compétentes numériquement, avec des conséquences potentielles sur l’équité, la responsabilité et le professionnalisme dans les marchés du logement.Originalité et valeurCette étude propose une explication psychologique inédite de la baisse de satisfaction des acheteurs dans les transactions avec agents, malgré des résultats objectifs équivalents. Elle met en lumière comment la perception des coûts d’opportunité et les biais cognitifs influencent l’évaluation de l’intermédiation dans l’immobilier