Episciences.org
Not a member yet
6707 research outputs found
Sort by
Effective quantum dynamics for magnetic fermions
No full textWe show how to derive an effective nonlinear dynamics, described by theHartree-Fock equations, for fermionic quantum particles confined to atwo-dimensional box and in presence of an external, uniform magnetic field. Thederivation invokes the Dirac-Frenkel principle. We discuss the validity of thiseffective description with respect to the many-body Schr\"odinger dynamics forsmall times and for weak interactions, and also in regards to the number ofparticles.Comment: 31 pages, no figures. v2: matches published version on Open Communications in Nonlinear Mathematical Physic
Vers une participation effective des patients à la formation initiale des médecins : retour sur les travaux menés par le ministère chargé de la santé
No full textIn a context of increasing patient engagement in the French health system, the patient participation in medical education was encouraged in 2019 through a law. However, in the absence of an implementation framework, the deployment of this participation is encountering various obstacles. The French Ministry of Health has therefore launched a project to define benchmarks and identify levers to encourage its effective implementation. Under the guidance of a steering committee comprising the stakeholders, a review of the literature, several surveys and hearings of various involved players were carried out. This work resulted in 23 recommendations, covering reinforcement of patient engagement, recruitment and accompaniment of patients, employment framework and remuneration, and support structures. To enable these practices to be widely disseminated, we need to continue the work already underway to develop an environment and framework suitable for their deployment.Dans un contexte de développement de l’approche partenariale avec le patient, la participation des patients dans la formation des médecins a été encouragée en 2019 à travers une loi. Cependant, en l’absence de cadre d’application, la mise en place de cette participation rencontre différents obstacles. Le ministère chargé de la santé a donc mené un travail afin de définir des repères et d’identifier des leviers pour encourager sa mise en œuvre effective. Sous l’encadrement d’un comité de pilotage rassemblant les différentes parties prenantes, une revue de la littérature, différentes enquêtes, ainsi que des auditions auprès de différents acteurs impliqués ont été réalisées. Ce travail a abouti à 23 recommandations, portant sur l’affirmation de l’approche partenariale, le recrutement et l’accompagnement des patients partenaires, le cadre d’emploi et la rémunération, et la structuration de ce partenariat. Afin de permettre une diffusion large de ces pratiques, il est nécessaire de poursuivre le travail engagé pour développer un environnement et un cadre propice à son déploiement
Towards a Contemporary Philosophical Re-interpretation of Thorstein Veblenʼs Theory of Instincts and Institutions: An Axiomatic Approach
No full textThe break of the twentieth century has seen two fundamental theories challenging the fields of mathematics and (heterodox) economics-(ZFC) Set theory and Veblenʼs Institutionalist economics. Although no direct relationship between these diverse projects has ever been documented, this paper argues that Veblenʼs appropriation of psychological traits and instincts, resulting in a comprehensive social theory of institutional frameworks, utilizes a mode of axiomatic thinking analogous to constructing sets in mathematics. Contemporary philosophy and psychology have only recently shown how their theoretical cores can relate to set theory, potentially retroactively uncovering how Veblenʼs mode of thinking the relation instincts-habits of thought-institutions could be philosophically interpreted anew. This mode of inquiry thus also exposes the overarching, albeit implicit, aim of this paperto outline the preliminary steps towards a (continental) philosophically inspired critical theory of institutions relating to the critique of political economy
Dyck Words, Pattern Avoidance, and Automatic Sequences
No full textWe study various aspects of Dyck words appearing in binary sequences, where is treated as a left parenthesis and as a right parenthesis. We showthat binary words that are -power-free have bounded nesting level, butthis no longer holds for larger repetition exponents. We give an explicitcharacterization of the factors of the Thue-Morse word that are Dyck, and showhow to count them. We also prove tight upper and lower bounds on , thenumber of Dyck factors of Thue-Morse of length .Comment: Full version of a paper appearing in the conference proceedings of WORDS 202
A Faithful and Quantitative Notion of Distant Reduction for the Lambda-Calculus with Generalized Applications
No full textWe introduce a call-by-name lambda-calculus with generalizedapplications which is equipped with distant reduction. This allows to unblock-redexes without resorting to the standard permutative conversions ofgeneralized applications used in the original -calculus withgeneralized applications of Joachimski and Matthes. We show strongnormalization of simply-typed terms, and we then fully characterize strongnormalization by means of a quantitative (i.e. non-idempotent intersection)typing system. This characterization uses a non-trivial inductive definition ofstrong normalization --related to others in the literature--, which is based ona weak-head normalizing strategy. We also show that our calculus relates to explicit substitution calculi by means of a faithful translation, inthe sense that it preserves strong normalization. Moreover, our calculus and the original -calculus determine equivalent notionsof strong normalization. As a consequence, inherits a faithfultranslation into explicit substitutions, and its strong normalization can alsobe characterized by the quantitative typing system designed for ,despite the fact that quantitative subject reduction fails for permutativeconversions
Many-valued coalgebraic logic over semi-primal varieties
No full textWe study many-valued coalgebraic logics with semi-primal algebras oftruth-degrees. We provide a systematic way to lift endofunctors defined on thevariety of Boolean algebras to endofunctors on the variety generated by asemi-primal algebra. We show that this can be extended to a technique to liftclassical coalgebraic logics to many-valued ones, and that (one-step)completeness and expressivity are preserved under this lifting. For specificclasses of endofunctors, we also describe how to obtain an axiomatization ofthe lifted many-valued logic directly from an axiomatization of the originalclassical one. In particular, we apply all of these techniques to classicalmodal logic
Créations de plateformes numériques dans le secteur agricole français et logiques relationnelles : découplage ou encastrement ?
No full textCet article porte sur les dynamiques de l’encastrement relationnel des créateurs et créatrices de plateformes numériques dans le secteur agricole français, entreprises qui se sont considérablement développées ces dernières années. A partir d’une analyse qualitative et quantitative reposant sur des données mixtes collectées auprès d’entrepreneur.e.s, nous observons d’abord un processus de découplage, qui est majoritaire parmi les entrepreneur.e.s rencontré.es. Ces dernier.e.s n’échapperaient donc pas à la dynamique propre à « l’activité entrepreneuriale », à savoir le recours de plus en plus faible aux relations personnelles à mesure que l’entreprise se développe, phénomène qui a déjà été documenté par de nombreuses études. Toutefois, une analyse plus fine des profils montre que le taux d’encastrement d’une partie non négligeable des enquêté.e.s s’écarte de la distribution générale, ce qui interroge les conclusions d’ensemble. Un type de profil retient notamment notre attention, pour lequel le taux d’encastrement progresse au fil du temps. Nous montrons dans cet article que si cela est le signe pour certain.e.s d’une baisse d’activité de l’entreprise, pour d’autres il pourrait s’agir d’un mode original de développement. La singularité du monde professionnel sur lequel porte notre analyse (les mondes agricoles) et du type d’entreprise créée pourrait alors expliquer de tels résultats
Computing the unit group of a commutative finite -algebra
No full textFor a commutative finite -algebra, i.e., for a commutative ring whose additive group is finitely generated, it is known that the group ofunits of is finitely generated, as well. Our main results are algorithms tocompute generators and the structure of this group. This is achieved byreducing the task first to the case of reduced rings, then to torsion-freereduced rings, and finally to an order in a reduced ring. The simplified casesare treated via a calculation of exponent lattices and various algorithms tocompute the minimal primes, primitive idempotents, and other basic objects. Allalgorithms have been implemented and are available as a SageMath package.Whenever possible, the time complexity of the described methods is trackedcarefully.Comment: 16 pages; published in the journal of Groups, Complexity, Cryptolog
Lagrangian multiform structure of discrete and semi-discrete KP systems
No full textA variational structure for the potential AKP system is established using thenovel formalism of a Lagrangian multiforms. The structure comprises not onlythe fully discrete equation on the 3D lattice, but also its semi-discretevariants including several differential-difference equations asssociated with,and compatible with, the partial difference equation. To this end, an overviewis given of the various (discrete and semi-discrete) variants of the KP system,and their associated Lax representations, including a novel `generating PDE'for the KP hierarchy. The exterior derivative of the Lagrangian 3-form for thelattice potential KP equation is shown to exhibit a double-zero structure,which implies the corresponding generalised Euler-Lagrange equations. Alongsidethe 3-form structures, we develop a variational formulation of thecorresponding Lax systems via the square eigenfunction representation arisingfrom the relevant direct linearization scheme.Comment: 25 pages, 1 figur
Leanness Computation: Small Values and Special Graph Classes
No full textLet u and v be vertices in a connected graph G = (V, E). For any integer k such that 0 ≤ k ≤ dG (u, v), the k-slice Sk (u, v) contains all vertices x on a shortest uv-path such that dG (u, x) = k. The leanness of G is the maximum diameter of a slice. This metric graph invariant has been studied under different names, such as "interval thinness" and "fellow traveler property". Graphs with leanness equal to 0, a.k.a. geodetic graphs, also have received special attention in Graph Theory. The practical computation of leanness in real-life complex networks has been studied recently (Mohammed et al., COMPLEX NETWORKS'21). In this paper, we give a finer-grained complexity analysis of two related problems, namely: deciding whether the leanness of a graph G is at most some small value ℓ; and computing the leanness on specific graph classes. We obtain improved algorithms in some cases, and time complexity lower bounds under plausible hypotheses