Still Accelerating: Type Ia supernova cosmology is robust to host galaxy age evolution

International audienceType Ia supernovae are a cornerstone of modern cosmology, providing first evidence for cosmic acceleration and new tests of dark energy. Son et al. 2025 (S25) claim a strong redshift evolution in standardized supernova luminosities driven by supernova progenitor age, with dramatic cosmological implications: rapidly evolving dark energy, decelerating expansion, and a $9σ$ tension with $Λ$CDM. We show that the underpinning evidence required for this conclusion -- the supernova progenitor-age dependence, the redshift-dependent age difference, and their combined impact -- is either negligible or relies on effects already corrected for in modern supernova analyses. First, the S25 analysis omits the standard host-galaxy stellar mass correction that captures known environmental dependencies that also correlate with stellar age. Applying this correction to the S25 sample, we find no dependence of standardized supernova brightness on host age. Independent data also show no significant difference at low-redshift in standardized brightness between star-forming galaxies and several Gyr older quiescent galaxies of the same stellar mass. Second, the S25 scenario predicts strong redshift evolution of the host-mass effect. Data from the Dark Energy Survey supernova survey measure evolution of $-0.028 \pm 0.034~\mathrm{mag}\,z^{-1}$, consistent with zero and altering the dark-energy equation-of-state measurement ($w$) by $<$0.01 if included. Third, we demonstrate that the claimed $\sim5$~Gyr progenitor age difference between nearby and distant supernovae is overstated by factors of three to five largely due to a conflation of host galaxy age with supernova progenitor age. We conclude that type~Ia supernova cosmology remains robust for current measurements of dark energy

Considerations on the process of target selection for the Comet Interceptor mission

International audienceComet Interceptor is an ESA science mission with payload contributions from ESA Member States and with an international participation by JAXA. It is the first mission that is being designed, built, and potentially launched before its target is known. This approach will enable the spacecraft to perform the first mission to a Long Period Comet from the Oort Cloud, as these comets have fleeting visits to the inner Solar System lasting only months to years from first discovery, too short for the usual process of mission development to be followed. In this paper we describe a number of factors that need to be considered in selecting a target for the mission, including scientific, orbital, spacecraft and instrument constraints, and discussion of different prioritisation strategies. We find that, in the case where we have a choice of targets, our decisions will mostly be driven by orbital information, which we will have relatively early on, with information on the activity level of the comet an important but secondary consideration. As cometary activity levels are notoriously hard to predict based on early observations alone, this prioritisation / decision approach based more on orbits gives us confidence that a good comet that is compatible with the spacecraft constraints will be selectable with sufficient warning time to allow the mission to intercept it

Multibanded Reduced Order Quadrature Techniques for Gravitational Wave Inference

International audienceReduced-order quadrature (ROQ) is commonly used to speed up parameter estimation in gravitational wave astronomy; however, the construction of ROQ bases can be computationally costly, particularly for longer duration signals. We propose a modified construction strategy based on PyROQ that accelerates this process by performing the basis search using multiband waveforms, without compromising the desired likelihood speed and accuracy. We use this altered method to construct a set of ROQs in the sub-solar mass range using the \texttt{IMRPhenomXAS\_NRTidalV3} waveform. We find a 20% to 30% decrease in basis size and a $\sim 10$ times decrease in basis construction time. We verify the altered method preserves the likelihood accuracy and mantains consitent parameter estimation results

New Insights on Scalar Promotion with the Polyhedral Model

International audienceMemory accesses are a well known bottleneck whose impact might be mitigated by using properly the memory hierarchy until registers. In this paper, we address scalar promotion, a technique to turn temporary arrays into a collection of scalar variables to be allocated to registers. We revisit array scalarization in the light of the recent advances of the polyhedral model. We propose a general algorithm for array scalarization and we show a scalarization of stencil computations thanks to a preliminary preprocessing. Our scalarization algorithm operates on the polyhedral intermediate representation and could be plugged in a polyhedral compiler among other passes. In particular, our scalarization algorithm is parametrized by the program schedule, possibly computed by a previous compilation pass. We present a preliminary experimental validation with promising results

Experimental Demonstration of an IGCT/SiC PiN Diode Switching Cell Operating Without Any Turn-On Snubber

International audienceIGCTs are attractive for high power, low-frequency converters such as HVdc MMCs because of their lower losses compared to IGBTs. However, a drawback of IGCTs is that they typically require an additional and bulky turn-on snubber circuit to limit their turn-on dI/dt. This limitation in current dynamics prevents destructive recovery from occurring in the diode of an IGCT/diode switching cell. Previous studies have shown the possibility of removing the snubber by setting strict limits to the operating range of the IGCT/Si-diode pair, which in practice strongly restrain the application of a snubberless IGCT submodule or switching cell.In this article, high-voltage, high-current, SiC PiN diodes are used successfully with IGCTs in a snubberless configuration up to 4 kV/500 A, and a comparison is made with IGCTs operating with Si PiN diodes. The IGCT turn-on behavior is analyzed, through the evaluation of the IGCT equivalent resistance during turn-on. The impact of very short reverse recovery (RR) is also investigated, with the observation and analysis of the shared voltage between the IGCT and the diode and its impact. It is found that SiC PiN diodes can operate with IGCTs without the limitations encountered with Si diodes and without requiring a turn-on snubber

Unraveling the role of iron in electrolysis-peroxyacetic acid synergy for waste activated sludge dewaterability enhancement

fffInternational audienceliste mot clef

La mobilité durant la vie et les fonctionnements sociaux des premiers agropasteurs du Néolithique à partir des isotopes de l’oxygène et du strontium

International audienceLe développement d’études pluridisciplinaires croisant données biochimiques et génétiques a démontré que les fonctionnements de certains groupes néolithiques étaient fortement liés au sexe des individus au travers de mobilités spécifiques pour les femmes, de patrilinéarités dans les recrutements des ensembles funéraires et de possibles fonctionnements patrilocaux. Dans la continuité de ces travaux, le projet WomenSOFar (ANR-21-CE03-0008) explore les différences liées au sexe et aux moments de la vie dans les organisations sociales des premiers groupes d’agropasteurs d’Europe de l’Ouest et d’Afrique du Nord.En nous appuyant sur un corpus de 155 échantillonnages réalisés sur l’émail de molaires, nous avons étudié les variations dans les signaux isotopiques (87Sr/86Sr, δ18O) au cours de la période de formation des couronnes dentaires de 74 individus datés du Néolithique moyen (4500-3300 BCE) provenant du Bassin Parisien, du Massif Central, de la Vallée du Rhône et de la Côte Méditerranéenne. Nous avons comparé ces variations à des référentiels publiés et inédits sur les isotopes biodisponibles localement. Nous avons employé des modélisations statistiques pour caractériser les mobilités au cours de la vie et les différences dans les histoires de vie entre les femmes et les hommes.Les résultats montrent une importante variation des rapports isotopiques principalement pour des sujets féminins, et de façon plus prononcée sur la côte méditerranéenne. Des changements d’environnement peuvent avoir lieu durant l’enfance et l’adolescence, soulignant l’importance de la relation entre âge et statut social. L’emploi de mesures multiples par individus montre des trajectoires individuelles variées : certains individus se déplacent vers de nouveaux environnements, d’autres semblent quitter puis revenir dans les environnements de leur enfance. Ces données mettent en évidence l’importance des histoires individuelles ainsi que des identités biologiques et sociales dans les fonctionnements des groupes étudiés

HARMONY: A Holistic Auto-Scaling Resilient Model for Multi-Objective Adaptation in Microservices Using HPPNs—A Case Study on E-Business Platforms

International audienc

Sentir l’indémontrable. Leibniz, Mariotte, et les définitions comme vérités premières (1676) [version auteur, non corrigée]

International audienc

Comparative effectiveness of tofacitinib versus upadacitinib for the treatment of acute severe ulcerative colitis

International audienceBackground and aims: Tofacitinib and upadacitinib are Janus kinase (JAK) inhibitors that are increasingly used for the treatment of acute severe ulcerative colitis (ASUC). However, comparative analyses of safety and effectiveness have not been performed for their use in this setting.Methods: This multicenter, retrospective study enrolled hospitalized adult patients treated with tofacitinib or upadacitinib for ASUC between January 2019 and June 2024. The main outcomes were clinical response, clinical remission, and colectomy-free survival. Propensity-adjusted analyses using inverse probability treatment weighting (IPTW), and double robust estimations (DRE) were used to control for confounding factors.Results: In total, 111 patients (60 tofacitinib, 51 upadacitinib) were enrolled across 23 international centers. JAK inhibitors were used to induce response in 86 (77%) patients and used to maintain response after adequate intravenous steroid response in 25 (23%). The median follow up was 31 weeks (IQR 13-64). Between days 3-7 after treatment initiation, upadacitinib was associated with greater response rates 84% vs.54%,p=0.02 but response/remission were comparable at day 98 (45%/36% vs 55/48%) and day 182 (29/29% vs. 39/34%). Sub-analyses for JAK inhibitor use as salvage therapy (tofacitinib (n=35) vs. upadacitinib (n=31)) showed similar effectiveness outcomes across both groups. The probabilities of colectomy-free survival at days 98/182 for tofacitinib and upadacitinib were 79%/75% and 80%/78%, respectively, with no significant differences in the comparison of survival curves, p=0.99. Treatment failure rates (where JAK inhibitor was used to maintain remission) were similar at days 98 and 182. The frequency of adverse events was comparable.Conclusion: Tofacitinib and upadacitinib appear to have similar effectiveness and safety profiles when used for the treatment of ASUC