Bose-Einstein Condensation in the Luttinger-Sy Model

We present a rigorous study of the Bose-Einstein condensation in the Luttinger-Sy model. We prove the existence of the condensation in this one-dimensional model of the perfect boson gas placed in the Poisson random potential of singular point impurities. To tackle the off-diagonal long-range order we calculate explicitly the corresponding space-averaged one-body reduced density matrix. We show that mathematical mechanism of the Bose-Einstein condensation in this random model is similar to condensation in a one-dimensional nonrandom hierarchical model of scaled intervals. For the Luttinger-Sy model we prove the Kac-Luttinger conjecture, i.e., that this model manifests a type I BEC localized in a single "largest" interval of logarithmic size

Single index regression models in the presence of censoring depending on the covariates

Consider a random vector (X',Y)', where X is d-dimensional and Y is one-dimensional. We assume that Y is subject to random right censoring. The aim of this paper is twofold. First, we propose a new estimator of the joint distribution of (X',Y)'. This estimator overcomes the common curse-of-dimensionality problem, by using a new dimension reduction technique. Second, we assume that the relation between X and Y is given by a mean regression single index model, and propose a new estimator of the parameters in this model. The asymptotic properties of all proposed estimators are obtained.Comment: Published in at http://dx.doi.org/10.3150/12-BEJ464 the Bernoulli (http://isi.cbs.nl/bernoulli/) by the International Statistical Institute/Bernoulli Society (http://isi.cbs.nl/BS/bshome.htm

Big Brother Logic: Logical modeling and reasoning about agents equipped with surveillance cameras in the plane

International audienceWe consider multi-agent scenarios where each agent control sa surveillance camera positioned in the plane, with xed position and angle of view, but rotating freely. The agents can thus observe the surroundings and each other. They can also reason about each other's observation abilities and knowledge derived from these observations. We introduce suitable logical languages for reasoning about such scenarios which involve atomic formulae stating what agents can see, multi-agent epistemic operators for individual, distributed and common knowledge, as well as dynamic operators reflecting the ability of cameras to turn around in order to reach positions satisfying formulae in the language. We introduce semantics of our basic logic BBL and its extensions on natural geometric models, as well as formal Kripke semantics for them in vision-based nite abstractions of the geometric models. We discuss the expressiveness of our logical languages and provide their translations in PDL style. Using these translations we develop algorithms and obtain complexity results for model checking and satisability testing for BBL and its extensions. Notably, we show that even for the extension with common knowledge, model checking remains in PSPACE. Finally, we discuss some further extensions: by adding obstacles, positioning the cameras in 3D or enabling them to change positions

Electrochemical impedance spectroscopy to study physiological changes affecting the red blood cell after invasion by malaria parasites

The malaria parasite, Plasmodium falciparum, invades human erythrocytes and induces dramatic changes in the host cell. The idea of this work was to use RBC modified electrode to perform electrochemical impedance spectroscopy (EIS) with the aim of monitoring physiological changes affecting the erythrocyte after invasion by the malaria parasite. Impedance cell-based devices are potentially useful to give insight into cellular behavior and to detect morphological changes. The modelling of impedance plots (Nyquist diagram) in equivalent circuit taking into account the presence of the cellular layer, allowed us pointing out specific events associated with the development of the parasite such as (i) strong changes in the host cell cytoplasm illustrated by changes in the film capacity, (ii) perturbation of the ionic composition of the host cell illustrated by changes in the film resistance, (iii) releasing of reducer (lactic acid or heme) and an enhanced oxygen consumption characterized by changes in the charge transfer resistance and in the Warburg coefficient characteristic of the redox species diffusion. These results show that the RBC-based device may help to analyze strategic events in the malaria parasite development constituting a new tool in antimalarial research

Radio wavefront of very inclined extensive air-showers observed with extended and sparse radio arrays

In this article we perform a simulation-based study of the shape of the electromagnetic wavefront of air showers induced by cosmic rays. We show that for showers with zenith angles larger than 60{\deg}, a point-source like description of the wave-front is sufficient and that the reconstructed position of this point-source is a potential proxy for the determination of the nature of the cosmic rays initiating the showers, with performances similar to those obtained using the depth of shower maximum.Comment: 16 pages, 8 figures. arXiv admin note: text overlap with arXiv:2107.0320

Effect of atmosphere change paths on the induced chemical expansion

International audienceThis study presents the relevant aspects of the approach developed at Institut PRISME to model strain in the mixed ionic and electronic conductors (MIEC) membrane for reforming of methane into synthesis gas (H2/CO). This macroscopic approach is based on the assumption of strain partition and on the choice of oxygen activity as a state variable. It leads to a thermo-chemo-mechanical model taking into account oxygen diffusion as well as elastic, thermal and chemical expansion phenomena. A chemical expansion model is proposed. The kinetics of a macroscopic bulk diffusion model has been fitted by simulation to chemical dilatometry tests. The transient and the steady-state stress distribution in a membrane reactor for partial oxidation of methane (POM) have been simulated in various conditions