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Probing anyon statistics on a single-edge loop in the fractional quantum Hall regime
No full textInternational audienceWe propose a setup to directly measure the anyonic statistical angle on a single edge of a fractional quantum Hall system, without requiring independent knowledge of non-universal parameters. We consider a Laughlin edge state bent into a closed loop geometry, where tunneling processes are controllably induced between the endpoints of the loop. To illustrate the underlying physical mechanism, we compute the time-dependent current generated by the injection of multiple anyons, and show that its behavior exhibits distinctive features governed by the anyonic statistical angle. The measured current reflects quantum interference effects due to the time-resolved braiding of anyons at the junction. To establish experimental relevance, we introduce a protocol where anyons are probabilistically injected upstream of the loop via a quantum point contact (QPC) source. Unlike in Fabry-Perot interferometers, where phase jumps occur spontaneously due to stochastic quasi-particle motion, here the phase jumps are deliberately induced by source injections. These events imprint measurable signatures in the cross-correlation noise, enabling a controlled statistical analysis of the braiding phase. We further show that, by varying the magnetic field while remaining within the same fractional quantum Hall plateau, the statistical angle can be extracted without relying on the knowledge of other non-universal system parameters. Our results provide a minimal and accessible platform for probing anyonic statistics using a single chiral edge
Quelle(s) Cité(s) idéale(s) ?
No full textInternational audienceيدرس هذا المقال مفهوم المدينة المثالية من منظور فلسفي وسياسي وجمالي. وانطلاقًا من لوحات عصر النهضة للمدينة المثالية التي تعود إلى عصر النهضة، وهي لوحات رائعة ولكنها خالية من أي طابع إنساني، يسلط الكاتب الضوء على غموض المثالية العقلانية غير الإنسانية وغير القابلة للوصول إليها. فالمدينة سياسية في المقام الأول وليست حضرية. يُظهر تحليل لرسائل مونتسكيو الفارسية أن كل تنظيم بشري يتطلب الفضيلة، لكن هذا التنظيم يتآكل مع الرفاهية والثروة، مما يستلزم قوانين وحكومة. في كتاب "القوانين"، يقترح أفلاطون مدينة صارمة وتراتبية تقوم على الفضيلة، ولكن على حساب السيطرة الاجتماعية والديموغرافية القصوى: فهي بعيدة كل البعد عن المثالية، بل هي نموذج شمولي. وعلى النقيض من ذلك، ترسم يوتوبيا توماس مور نموذجًا للشيوعية القائمة على المساواة والسلام، متخفيًا في شكل سرد حواري ينتقد فيه المؤلف إنجلترا في عصره. وأخيرًا، يدرس المقال "المدينة" المعاصرة، المختزلة في أطرافها المهمشة، وهي انعكاس لديمقراطية تمثيلية يصادرها الخبراء. يتم استبدال المدينة الحقيقية، كمشروع جماعي، بمدينة تكنوقراطية. هذا التخلي عن المثل الأعلى السياسي، لصالح التفويض، يمثل انحلال المدينة.Der Artikel hinterfragt den Begriff der idealen Stadt, indem er philosophische, politische und ästhetische Sichtweisen kreuzt. Ausgehend von den prächtigen, aber menschenleeren Gemälden der Città Ideale aus der Renaissance betont der Autor die Ambiguität eines unmenschlichen, unerreichbaren, rationalen Ideals. Die Stadt ist dort in erster Linie politisch und nicht städtisch. Die Analyse von Montesquieus "Lettres persanes" zeigt, dass jede menschliche Organisation Tugend erfordert, dass diese aber mit Komfort und Reichtum erodiert und Gesetze und eine Regierung erforderlich macht. Platon schlägt in Die Gesetze eine starre, hierarchische Stadt vor, die auf Tugend beruht, aber um den Preis einer extremen sozialen und demografischen Kontrolle: weit entfernt von einem Ideal, ein totalitäres Modell. Im Gegensatz dazu skizziert Thomas Mores Utopia einen egalitären und friedlichen Kommunismus, der sich hinter dem Gewand einer dialogischen Erzählung verbirgt, in der der Autor das England seiner Zeit kritisiert. Schließlich befasst sich der Artikel mit der zeitgenössischen "Stadt", die auf ihre marginalisierten Randgebiete reduziert ist und eine repräsentative Demokratie widerspiegelt, die von Experten beschlagnahmt wurde. Die wahre Stadt als kollektives Projekt verschwindet zugunsten einer technokratischen Stadt. Dieser Verzicht auf das politische Ideal zugunsten der Delegation markiert die Auflösung der Cité.This article examines the notion of the ideal city from a philosophical, political and aesthetic perspective. Starting with the Renaissance paintings of the Città ideale, which are magnificent but devoid of any humanity, the author highlights the ambiguity of a rational ideal that is inhuman and inaccessible. The city is primarily political, not urban. An analysis of Montesquieu's Persian Letters shows that all human organisation requires virtue, but that this erodes with comfort and wealth, necessitating laws and government. In The Laws, Plato proposes a rigid, hierarchical city founded on virtue, but at the cost of extreme social and demographic control: far from an ideal, it is a totalitarian model. In contrast, Thomas More's Utopia sketches out an egalitarian and peaceful communism, disguised as a dialogue-based narrative in which the author criticises the England of his time. Finally, the article examines the contemporary 'city', reduced to its marginalised peripheries, a reflection of a representative democracy confiscated by experts. The real city, as a collective project, is being replaced by a technocratic city. This renunciation of the political ideal, in favour of delegation, marks the dissolution of the City.Este artículo examina la noción de ciudad ideal desde una perspectiva filosófica, política y estética. Partiendo de las pinturas renacentistas de la Città ideale, magníficas pero desprovistas de toda humanidad, el autor pone de relieve la ambigüedad de un ideal racional inhumano e inaccesible. La ciudad es ante todo política, no urbana. El análisis de las Cartas persas de Montesquieu muestra que toda organización humana requiere virtud, pero que ésta se erosiona con la comodidad y la riqueza, haciendo necesarias leyes y gobierno. En Las Leyes, Platón propone una ciudad rígida y jerárquica fundada en la virtud, pero a costa de un control social y demográfico extremo: lejos de ser un ideal, es un modelo totalitario. Por el contrario, la Utopía de Tomás Moro esboza un comunismo igualitario y pacífico, disfrazado de narración dialogada en la que el autor critica la Inglaterra de su tiempo. Por último, el artículo examina la "ciudad" contemporánea, reducida a sus periferias marginales, reflejo de una democracia representativa confiscada por los expertos. La ciudad real, como proyecto colectivo, está siendo sustituida por una ciudad tecnocrática. Esta renuncia al ideal político, en favor de la delegación, marca la disolución de la Ciudad.L’article interroge la notion de cité idéale, en croisant les regards philosophiques, politiques et esthétiques. Partant des tableaux renaissants de la Città ideale, magnifiques mais vides de toute humanité, l’auteur souligne l’ambiguïté d’un idéal rationnel inhumain, inaccessible. La cité y est d’abord politique, non urbaine. L’analyse des Lettres persanes de Montesquieu montre que toute organisation humaine requiert vertu, mais que celle-ci s’érode avec le confort et la richesse, nécessitant lois et gouvernement. Platon propose, dans Les Lois, une cité rigide et hiérarchisée, fondée sur la vertu, mais au prix d’un contrôle social et démographique extrême : loin d’un idéal, un modèle totalitaire. À l’inverse, Utopia de Thomas More esquisse un communisme égalitaire et pacifique, dissimulé sous les oripeaux d’un récit dialogué, où l’auteur critique l’Angleterre de son temps. Enfin, l’article interroge la "cité" contemporaine, réduite à ses périphéries marginalisées, reflet d’une démocratie représentative confisquée par les experts. La cité véritable, comme projet collectif, s’efface au profit d’une ville technocratique. Ce renoncement à l’idéal politique, au profit de la délégation, marque la dissolution de la Cité.Questo articolo esamina la nozione di città ideale da una prospettiva filosofica, politica ed estetica. Partendo dai dipinti rinascimentali della Città ideale, magnifici ma privi di umanità, l'autore mette in luce l'ambiguità di un ideale razionale, disumano e inaccessibile. La città è innanzitutto politica, non urbana. Un'analisi delle Lettere persiane di Montesquieu mostra che ogni organizzazione umana richiede la virtù, ma che questa si erode con il benessere e la ricchezza, rendendo necessarie leggi e governo. Nelle Leggi, Platone propone una città rigida e gerarchica fondata sulla virtù, ma a costo di un estremo controllo sociale e demografico: lungi dall'essere un ideale, è un modello totalitario. Al contrario, l'Utopia di Tommaso Moro tratteggia un comunismo egualitario e pacifico, mascherato da una narrazione dialogica in cui l'autore critica l'Inghilterra del suo tempo. Infine, l'articolo esamina la "città" contemporanea, ridotta alle sue periferie emarginate, riflesso di una democrazia rappresentativa confiscata dagli esperti. La città reale, come progetto collettivo, viene sostituita da una città tecnocratica. Questa rinuncia all'ideale politico, a favore della delega, segna la dissoluzione della città.Este artigo examina a noção de cidade ideal numa perspetiva filosófica, política e estética. Partindo das pinturas renascentistas da Città ideale, magníficas mas desprovidas de qualquer humanidade, o autor sublinha a ambiguidade de um ideal racional, desumano e inacessível. A cidade é antes de mais política e não urbana. A análise das Cartas Persas de Montesquieu mostra que toda a organização humana requer a virtude, mas que esta se desgasta com o conforto e a riqueza, necessitando de leis e de governo. Em As Leis, Platão propõe uma cidade rígida e hierarquizada, fundada na virtude, mas à custa de um controlo social e demográfico extremo: longe de ser um ideal, é um modelo totalitário. Em contrapartida, a Utopia de Thomas More esboça um comunismo igualitário e pacífico, disfarçado numa narrativa dialogada em que o autor critica a Inglaterra do seu tempo. Por fim, o artigo analisa a "cidade" contemporânea, reduzida às suas periferias marginalizadas, reflexo de uma democracia representativa confiscada pelos especialistas. A cidade real, enquanto projeto coletivo, é substituída por uma cidade tecnocrática. Esta renúncia ao ideal político, a favor da delegação, marca a dissolução da Cidade.В статье рассматривается понятие идеального города с философской, политической и эстетической точек зрения. Начиная с ренессансных картин идеального города, великолепного, но лишенного человечности, автор подчеркивает двусмысленность рационального идеала, который является нечеловеческим и недоступным. Город в первую очередь политический, а не урбанистический. Анализ "Персидских писем" Монтескье показывает, что любая человеческая организация требует добродетели, но она разрушается с ростом комфорта и богатства, что приводит к необходимости создания законов и правительства. В "Законах" Платон предлагает жесткий, иерархический город, основанный на добродетели, но ценой жесточайшего социального и демографического контроля: это далеко не идеал, а тоталитарная модель. Напротив, в "Утопии" Томаса Мора намечается эгалитарный и мирный коммунизм, замаскированный под диалогическое повествование, в котором автор критикует Англию своего времени. Наконец, в статье рассматривается современный "город", сведенный к маргинальным перифериям, отражение представительной демократии, конфискованной экспертами. Реальный город как коллективный проект заменяется технократическим городом. Этот отказ от политического идеала в пользу делегирования полномочий знаменует собой распад города.本文从哲学、政治和美学的角度探讨了理想城市的概念。 作者从文艺复兴时期的理想城市绘画入手，强调了非人性和难以接近的理性理想的模糊性。 城市主要是政治性的，而非都市性的。 对孟德斯鸠《波斯书信集》的分析表明，所有人类组织都需要美德，但美德会随着舒适和财富的增加而削弱，因此需要法律和政府。 在《法律篇》中，柏拉图提出了一个建立在美德基础上的等级森严的城市，但代价是极端的社会和人口控制：这远非理想，而是一种极权模式。 与此相反，托马斯-莫尔的《乌托邦》勾画了一个平等、和平的共产主义，作者以对话的形式对当时的英国进行了批判。 最后，文章探讨了被边缘化的当代 "城市"，它反映了被专家没收的代议制民主。 真正的城市，作为一个集体项目，正在被技术官僚城市所取代。 放弃政治理想，转而采用授权方式，标志着城市的解体
Singular values-driven automated filter pruning
No full textInternational audienceIn this paper, we present SLIMING (Singular vaLues-drIven autoMated filter prunING), an automated filter pruning method that uses singular values to formalize the pruning process as an optimization problem over filter tensors. Recognizing that this original formulation poses a combinatorial challenge, we propose to replace it with a two-step process that consistently uses singular values in each phase: determining the pruning configuration, which specifies the number of filters to retain in each layer, and selecting the filters themselves. We show that this approach ensures the preservation of the filters' multidimensional structure throughout the pruning process. For each of these steps, we propose a straightforward algorithm to solve them. To validate each part of our approach, we performed a numerical simulation on an overparameterized synthetic toy example. Additionally, we conducted extensive simulations across eight architectures, four benchmark datasets, and four vision tasks, validating the efficacy of our framework. Our code is available for research purposes at \href{https://sliming-ai.github.io/}{\color{blue}{sliming-ai.github.io}}
A Collapse of the Parity Index Hierarchy of Tree Automata, Based on Cantor-Bendixson Ranks
No full textInternational audienceOver words, nondeterministic Büchi automata and alternating weak automata are as expressive as parity automata with any number of priorities. Over trees, the Büchi acceptance condition is strictly weaker and the more priorities we allow, the more languages parity automata can recognise. We say that on words, the parity-index hierarchies of nondeterministic and alternating automata collapse to the Büchi and weak level, respectively, while both are infinite over trees.We ask when is Büchi enough?, that is, on which classes of trees are nondeterministc Büchi automata as expressive as parity automata. Similarly for alternating weak automata. We work in the setting of unranked unordered trees, in which there is no order among the children of nodes.We find that for nondeterministic and alternating automata, the parity-index hierarchy collapses to the Büchi level and weak level, respectively, for any class of trees of finitely bounded Cantor-Bendixson rank, a topological measure of tree complexity. Over trees of countable Cantor-Bendixson rank, (a.k.a. thin trees) the parity-index hierarchy of both nondeterministic and alternating automata collapses to the level [1, 2, 3], as was already known for ordered trees. These results are in some sense optimal: on the class of trees of finite but unbounded Cantor-Bendixson rank, two priorities do not suffice to recognise all parity-recognisable languages, even for alternating automata
The 2-Token Theorem: Recognising History-Deterministic Parity Automata Efficiently
No full textInternational audienceHistory-determinism is a restricted notion of nondeterminism in automata, where the nondeterminism can be successfully resolved based solely on the prefix read so far. History-deterministic automata still allow for exponential succinctness in automata over infinite words compared to deterministic automata (Kuperberg and Skrzypczak, 2015), allow for canonical forms unlike deterministic automata (Abu Radi and Kupferman, 2019 and 2020; Ehlers and Schewe, 2022), and retain some of the algorithmic properties of deterministic automata, for example for reactive synthesis (Henzinger and Piterman, 2006; Ehlers and Khalimov, 2024). Despite the topic of history-determinism having received a lot of attention over the last decade, the complexity of deciding whether a parity automaton is history-deterministic has, up till now, remained open. We show that history-determinism for a parity automaton with a fixed parity index can be checked in PTIME, thus improving upon the naive EXPTIME upper bound of Henzinger and Piterman that has stood since 2006. More precisely, we show that the so-called 2-token game, which can be solved in PTIME for parity automata with a fixed parity index, characterises history-determinism for parity automata. This game was introduced by Bagnol and Kuperberg in 2018, who showed that to decide if a Büchi automaton is history-determinism, it suffices to find the winner of the 2-token game on it. They conjectured that this 2-token game based characterisation extends to parity automata. Boker, Kuperberg, Lehtinen, and Skrzypcak showed in 2020 that this conjecture holds for coBüchi automata as well. We prove Bagnol and Kuperberg's conjecture that the winner of the 2-token game characterises history-determinism on parity automata
Patterns and drivers of diatom diversity and abundance in the global ocean
No full textMany information about code and data availability at :https://www.nature.com/articles/s41467-025-58027-7#data-availabilityhttps://www.nature.com/articles/s41467-025-58027-7#code-availabilityInternational audienceDiatoms constitute one of the most diverse and ecologically important phytoplankton groups, yet their large-scale diversity patterns and drivers of abundance are unclear due to limited observations. Here, we utilize Tara Oceans molecular and morphological data, spanning pole to pole, to describe marine diatom diversity, abundance, and environmental adaptation and acclimation strategies. The dominance of diatoms among phytoplankton in terms of relative abundance and diversity is confirmed, and the most prevalent genera are Chaetoceros , Thalassiosira , Actinocyclus and Pseudo-nitzschia . We define 25 distinct diatom communities with varying environmental preferences illustrative of different life strategies. The Arctic Ocean stands out as a diatom hotspot with 6 of the diatom communities being exclusive to it. Light harvesting and photoprotection are among the cellular functions in which natural diatom populations invest the bulk of their transcriptional efforts. This comprehensive study sheds light on marine diatom distributions, offering insights to assess impacts of global change and oceanic anthropogenic impacts
Disparities in Daily Mobility: The Case of Immigrant Travel Speeds in France
No full textThis study investigates disparities in travel speeds between immigrants and natives in France. Using data from the 2019 French National Transport Survey, it examines the factors contributing to slower travel speeds among immigrants compared to natives. The findings highlight significant variability in travel speed behaviors between natives and immigrants and within immigrant subgroups. Immigrants' slower travel speeds are primarily driven by differences in transport mode choice, influenced by structural factors such as residential location. Immigrants without French citizenship exhibit lower travel speeds, supporting the "travel assimilation" hypothesis. Residing in immigrantdense neighborhoods or ethnic enclaves is associated with reduced travel speeds.</div
Clustered Correlation Health Scan Anomaly Detection Algorithm Applied for Fault Diagnosis in the Cylinders of a Marine Dual-Fuel Engine
No full textInternational audienceA novel anomaly detection algorithm is presented to analyze a group of signals that must be correlated under normal conditions. The method is called Clustered Correlation Health Scan (CCH-Scan). It detects abnormal signals, the durations corresponding to abnormalities, and the degree of abnormality. This algorithm is applied to a case study on fault diagnosis in the cylinders of a 12-cylinder marine dual-fuel engine. In particular, 12 Exhaust Valve Closing Dead Time (ECDT) signals are analyzed to detect abnormalities. Although these signals are critical and any abnormality in them requires urgent intervention, this is the first time they have been discussed in the literature. The details of the algorithm are elaborated, its parameters are studied, and the effects of these parameters on the results are measured and analyzed using a quality score. In addition, a metric to measure the degree of abnormality of the signal is introduced. The method detects abnormal signals, the durations of abnormalities, and the degrees of abnormalities. The results align with ground-truth data from an available technical industrial maintenance report. The approach demonstrates promising potential for application in various other contexts
Hybrid Quantum-Classical Algorithm for Hydrodynamics
No full textInternational audienceA new model of nonlinear charged quantum relativistic fluids is presented. This model can be discretized into Discrete Time Quantum Walks (DTQWs), and a new hybrid (quantum-classical) algorithm for implementing these walks on NISQ devices is proposed. High resolution (up to grid points) hybrid numerical simulations of relativistic and non-relativistic hydrodynamical shocks on current IBM NISQs are performed with this algorithm and shown to reproduce equivalent simulations on classical computers. This work demonstrates that nonlinear fluid dynamics can be simulated on NISQs, and opens the door to simulating other, quantum and non-quantum fluids, including plasmas, with more general quantum walks and quantum automata
Relire avec des « lunettes logistiques » la contribution de Jared Diamond sur le processus historique d'expansion des sociétés humaines
No full textInternational audienceRelire avec des « lunettes logistiques » la contribution de Jared Diamond sur le processus historique d'expansion des sociétés humaine