Les mariages clandestins: impasse disciplinaire, scandale ou moteur de la réflexion doctrinale?

The history of the formalization of marriage law in the Latin medieval West is very much like a series of normative tensions. Although the conflicts of norms cannot be restricted to theological and legal controversies, their interest lies in the fact that they sometimes gave rise to the expression of contradictory norms, depending on the forum at stake. It was more particularly the case when it came to the question of settling the moral and judiciary issues in connexion with the hierarchical status of clandestine marriages and that of public ones, or the one of a “sexual intercourse followed by words of future” and that of a marriage contracted by “words of present”. Which of these processes guaranteed a « true » marriage ?  And according to which normative references ? The different solutions provided by canonical doctrine, theology, the manuals for parish priests and confessors or even synodal statutes enable us to assess the different goals of the clerics concerned by matrimonial issues. Much is at stake, because what is concerned is the salvation of the laity and the balance of the whole society. These normative tensions sometimes led to conceptual and lexical evolutions, but they also entailed certain forms of competition that could undermine the usual means of social regulation, which the actors of matrimonial could sometimes take advantage of

Large amplitude dynamics of micro/nanomechanical resonators actuated with electrostatic pulses

International audienceIn the field of resonant NEMS design, it is a common misconception that large-amplitude motion, and thus large signal-to-noise ratio, can only be achieved at the risk of oscillator instability. In the present paper, we show that very simple closed-loop control schemes can be used to achieve stable largeamplitude motion of a resonant structure, even when jump resonance (caused by electrostatic softening or Duffing hardening) is present in its frequency response. We focus on the case of a resonant accelerometer sensing cell, consisting in a nonlinear clamped-clamped beam with electrostatic actuation and detection, maintained in an oscillation state with pulses of electrostatic force that are delivered whenever the detected signal (the position of the beam) crosses zero. We show that the proposed feedback scheme ensures the stability of the motion of the beam much beyond the critical Duffing amplitude and that, if the parameters of the beam are correctly chosen, one can achieve almost full-gap travel range without incurring electrostatic pull-in. These results are illustrated and validated with transient simulations of the nonlinear closed-loop system

Une bâtardise fictive : le personnage de Ferrand dans Baudouin de Flandre

L’article analyse les raisons pour lesquelles Baudouin de Flandre, roman en prose du XVe siècle, invente à son personnage de Philippe Auguste un fils bâtard, Ferrand de Portugal, créant ainsi un lien imaginaire entre deux des protagonistes de Bouvines. Le romancier rend en effet père et fils un roi Philippe trop porté sur les femmes et un Ferrand aux origines douteuses. Tandis que les quatre fils légitimes –inventés- protègent le royaume, le fils bâtard le menace dans son existence même. L’article est en quête de l’histoire réelle qui affleure sous la fiction (Mathilde de Portugal mère de Ferrand selon la rumeur, bâtardise de Philippe Hurepel, captivité de Renaud de Dammartin…). Le roman fait se confronter les méfaits de l’amour naturel à la légitimité sacrée du mariage monogamique. Ce dernier est incarné par un contre-modèle à Philippe Auguste, saint Louis, dont la fidélité conjugale est exaltée. Les fautes personnelles d’un roi rejaillissent sur la vie collective d’une nation et expliquent en l’occurrence les conflits franco-flamands

Effect of Electron Correlation on the Bragg Reflection

We study the effect of correlation on the Bragg reflection in the 3D electron gas, the 1D Luttinger liquid, and the 1D Hubbard model in an alternating periodic potential at half-filling. In the last system, we suggest a Luttinger-liquid-type quasi-metallic state in the crossover region from the band insulator to the Mott insulator. We explain the appearance of this state in terms of the incompatibility of the Bragg reflection with the concept of Luttinger liquids.Comment: 4 pages, 3 figure

Electron-Doped Manganese Perovskites: The Polaronic State

Using the Lanczos method in linear chains we study the ground state of the double exchange model including an antiferromagnetic super-exchange in the low concentration limit. We find that this ground state is always inhomogeneous, containig ferromagnetic polarons. The extention of the polaron spin distortion, the dispersion relation and their trapping by impurities, are studied for diferent values of the super exchange interaction and magnetic field. We also find repulsive polaron polaron interaction.Comment: 4 pages, 6 embedded figure

Phase diagram and optical conductivity of the one-dimensional spinless Holstein model

The effects of quantum lattice fluctuations on the Peierls transition and the optical conductivity in the one-dimensional Holstein model of spinless fermions have been studied by developing an analytical approach, based on the unitary transformation method. We show that when the electron-phonon coupling constant decreases to a finite critical value the Peierls dimerization is destroyed by the quantum lattice fluctuations. The dimerization gap is much more reduced by the quantum lattice fluctuations than the phonon order parameter. The calculated optical conductivity does not have the inverse-square-root singularity but have a peak above the gap edge and there exists a significant tail below the peak. The peak of optical-conductivity spectrum is not directly corresponding to the dimerized gap. Our results of the phase diagram and the spectral-weight function agree with those of the density matrix renormalization group and the exact diagonalization methods.Comment: 9 pages, 4 figures include