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Le séjour de Leibniz à Paris
No full textInternational audienceDu 5 au 7 décembre 2022, un colloque international s’est tenu à l’Hôtel de Lauzun pour commémorer les trois cent cinquante ans de l’arrivée de Leibniz à Paris. Cet événement fut la dernière rencontre scientifique à laquelleparticipa Maria Rosa Antognazza. Le présent volume est dédié à sa mémoire. Réunissant une trentaine de contributions, il explore cette période parisienne particulièrement prolifique, à la lumière des progrès récents de l’édition des manuscrits de Leibniz
Euclid preparation. Galaxy power spectrum modelling in redshift space
No full textInternational audienceAccurate modelling of redshift-space distortions (RSD) is essential for maximizing the cosmological information extracted from large galaxy redshift surveys. In preparation for the forthcoming analysis of the Euclid spectroscopic data, we investigate three approaches to modelling RSD effects on the power spectrum multipoles of mock H emission line galaxies. We focus on two one-loop perturbation theory models -- the effective field theory (EFT) and velocity difference generator () -- which differ in their treatment of the real-to-redshift space mapping on small scales, and a third approach, the BACCO emulator, which adopts a hybrid strategy combining perturbation theory with high-resolution N-body simulations. We assess the ability of these models to recover key cosmological parameters, including the expansion rate , the cold dark matter density parameter , and the scalar amplitude , across four redshift bins spanning . In each bin, we find that and BACCO outperform the EFT model across all scales up to . While BACCO saturates in constraining power at intermediate scales and higher redshift, the model continues to improve parameter constraints beyond . The EFT model, although robust on large scales, exhibits significant parameter biases for , limiting its applicability to Euclid-like H samples. Among the full perturbation theory-based models, the enhanced treatment of small-scale RSD effects in improves cosmological parameter constraints by up to a factor of two
Design of an eco-industrial park for hydrogen and Fischer–Tropsch fuel deployment under the European policy framework
No full textInternational audienceOptimizing the hydrogen economy within industrial hubs represents a key aspect contributing to global decarbonization, yet current design approaches often overlook macroeconomic constraints, synergy opportunities and actor cooperation dynamics. This study addresses these gaps by proposing a multi-period, multi-resource integration framework for evaluating the feasibility of Fischer–Tropsch fuel production within an Eco-Industrial Park (EIP). A Mixed Integer Linear Programming (MILP) model is developed to minimize the annualized net present value of the system, considering both cooperative and non-cooperative governance schemes. The model integrates macroeconomic parameters such as EU ETS market prices, carbon dioxide sequestration costs, and RFNBO regulations, factors rarely accounted for in hydrogen-related EIP design. Results show that electricity is the dominant feedstock cost driver, contributing five times more than carbon dioxide to synthetic fuel production costs. Under favorable conditions, synthetic fuels must be priced at least three times higher than conventional fuels to justify investment, while under unfavorable conditions, this threshold rises to nine times. Cooperative governance enables economic gains through synthetic fuel sales, heat valorization and hydrogen production scaling, whereas non-cooperative governance leads to higher synthetic fuel prices due to resource bidding dynamics. These bidding dynamics, especially regarding carbon dioxide, are deeply influenced by policies, hence, the study concludes that policy design, as well as actor coordination, are critical to the viability of hydrogen-based EIPs in Europe
Le racisme scientifique et médical: circulations internationales et résurgences, du XIXe siècle à nos jours
No full textInternational audienceUne étude sur le racisme scientifique, dans laquelle les autrices évoquent les trajectoires sociales, le contexte politique propice aux résurgences de mythes infondés, les stratégies mises en place pour faire accepter une forme de scientificité, entre autres
Schubert line defects in 3d GLSMs, part II: Partial flag manifolds and parabolic quantum polynomials
No full textInternational audienceWe construct Schubert line defects in the 3d supersymmetric gauged linear sigma model (GLSM) with target space a partial flag manifold , generalizing our construction for complete flag manifolds given in a companion paper arXiv:2512.19802 (part I). In the context of the 3d GLSM/quantum K-theory correspondence, the Schubert line defects are constructed as 1d supersymmetric gauge theories coupled to the 3d field theory, and they flow to objects supported on Schubert varieties in the quantum K-theory. The flavored Witten index of the 1d defect is expected to compute the Chern character of -- more precisely, it gives us a polynomial representative of the Schubert class in the quantum K-theory ring. We give strong evidence for this claim by showing in examples that the Witten indices of Schubert defects indeed reproduce a recently-defined set of polynomials that represent the Schubert classes in the Whitney presentation, which we call the parabolic Whitney polynomials. Moreover, upon using the quantum ring relations, we can convert these polynomials into seemingly new polynomials in the Toda presentation, which we call the parabolic quantum Grothendieck polynomials. These new polynomials specialize to known polynomials in various limits, including to the quantum Grothendieck polynomials in the case of the complete flag. In the 2d limit, our construction also realizes the Schubert classes in the quantum cohomology ring of the partial flag manifold, and the parabolic quantum Grothendieck polynomials then reduce to previously known parabolic quantum Schubert polynomials
Benchmark for two-dimensional large scale coherent structures in partially magnetized E × B plasmas—community collaboration & lessons learned
No full textInternational audienceAbstract Low-temperature plasmas (LTPs) are essential to both fundamental scientific research and critical industrial applications. As in many areas of science, numerical simulations have become a vital tool for uncovering new physical phenomena and guiding technological development. Code benchmarking remains crucial for verifying implementations and evaluating performance. This work continues the Landmark benchmark initiative, a series specifically designed to support the verification of LTP codes. In this study, seventeen simulation codes from a collaborative community of nineteen international institutions modeled a partially magnetized E × B Penning discharge. The emergence of large scale coherent structures, or rotating plasma spokes, endows this configuration with an enormous range of time scales, making it particularly challenging to simulate. The codes showed excellent agreement on the rotation frequency of the spoke as well as key plasma properties, including time-averaged ion density, plasma potential, and electron temperature profiles. Achieving this level of agreement came with challenges, and we share lessons learned on how to conduct future benchmarking campaigns. Comparing code implementations, computational hardware, and simulation runtimes also revealed interesting trends, which are summarized with the aim of guiding future plasma simulation software development
Automated mapping of DNA replication fork progression in human cells with ForkML
No full textInternational audienceCurrent approaches to mapping fork progression in the human genome suffer from drastically low throughput. Here, we introduce ForkML, a nanopore sequencing-based method automatically positioning thousands of individual fork velocities by tracking BrdU incorporation into replicating DNA after double pulse-labelling of asynchronous cells. ForkML recovers known human fork speed, accurately detects replication stress, and, crucially, connects replication dynamics to genomic and chromatin contexts, exposing fork slowdown in early-replicating transcribed regions
Impact of active galactic nuclei and nuclear star formation on the ISM turbulence of galaxies: Insights from JWST/MIRI spectroscopy
No full textInternational audienceActive galactic nuclei (AGNs), star formation (SF), and galaxy interactions can drive turbulence in the gas of the interstellar medium (ISM), which, in turn, plays a role in SF taking place within galaxies. The impact on molecular gas is of particular importance, as it serves as the primary fuel for SF. Our goal is to investigate the origin of turbulence and the emission of molecular gas, as well as low-and-intermediate-ionisation gas, in the inner few kpc of both AGN hosts and star-forming galaxies (SFGs). We used archival JWST MIRI/MRS observations of a sample consisting of 54 galaxies at z < 0.1. We present flux measurements for the H2 S(5)λ6.9091 μm, [ArII]λ6.9853 μm, [FeII]λ5.3403 μm, and [ArIII]λ8.9914 μm emission lines along with velocity dispersion estimated by the W80 parameter. For galaxies with coronal line emission, we included measurements of the [MgV]λ5.6098 μm line. We compared the line ratios to photoionisation and shock models to explore the origin of the gas emission. AGNs exhibit broader emission lines than SFGs, with the largest velocity dispersions observed in radio-strong (RS) AGNs. The H2 gas is less turbulent compared to ionised gas, while coronal gas presents higher velocity dispersions. The W80 values for the ionised gas show a decrease when going from the nucleus out to radii of approximately 0.5–1 kpc, followed by an outward increase up to 2–3 kpc. In contrast, the H2 line widths generally display increasing profiles with distance from the center. Correlations between the W80 parameter and line ratios such as H2S(5)/[Ar II] and [Fe II]/[Ar II] indicate that the most turbulent gas is associated with shocks, enhancing H2 and [Fe II] emissions. Based on the observed line ratios and velocity dispersions, the [FeII] emission is consistent with predictions of fast shock models, while the H2 emission is likely associated with molecules formed in the post-shock region. We speculate that these shocked gas regions are produced by AGN outflows and jet-cloud interactions in AGN-dominated sources; whereas in SFGs, they might be created through stellar winds and mergers. This shock-induced gas heating may be an important mechanism of AGN (or stellar) feedback, preventing the gas from cooling and forming new stars.Key words: galaxies: active / galaxies: evolution / galaxies: ISM / galaxies: kinematics and dynamic
Phénoménologie de la honte
No full textInternational audienceScheler, Sartre et Levinas proposent une véritable phénoménologie de la honte en mettant entre parenthèses toute causalité mondaine et en cherchant à mettre en lumière le phénomène pur de la honte. Scheler élucide le « se faire honte », Sartre décrit l’être hors de soi de la honte et Levinas l’exposition absolue de la honte. Ces trois figures de la honte convergent pour montrer que la honte peut aussi bien être un lieu d’enfermement que d’évasion et qu’elle est justement la possibilité de transformer cette fermeture en ouverture. Il s’agit alors de se demander si toutes les dimensions du phénomène de la honte sont prises en compte et s’il ne faut pas envisager la dimension commune de la honte avec la possibilité de se délivrer de sa honte en l’offrant.Plan -- Vers le phénomène pur de la honte -- Le « se faire honte » -- La honte comme chute originelle -- La honte comme exposition absolue -- Le don de sa hont
Na10Mn4O9: Synthesis, Structure, and Electrochemical Properties
No full textInternational audienceIn the search for sustainable cathode materials for Na–ion batteries, Mn-based oxides have emerged as attractive candidates owing to their earth abundance and structural versatility. In this context, a comprehensive investigation of the electrochemical behavior of the sodium-rich Mn2+ oxide Na10Mn4O9 toward sodium extraction/insertion is presented. The structural framework of this phase, prepared through a simple solid-state synthesis at 450 °C, is built on MnO4 and MnO3 polyhedra. Seven sodium ions per unit formula can be extracted during the first charge, and XAS analysis reveals the main transformation into a layered NaxMnO2·Na2O composite. Upon further cycling, once this phase is formed, the material delivers a reversible capacity of 110 mAh g–1 at an average potential of 2.24 V vs Na+/Na