L'effet Casimir est une prédiction de la théorie quantique des champs, à l’interface avec des problèmes ouverts de la physique fondamentale comme le problème de l'énergie du vide ou les tests de la loi de gravité à courte distance. L’expression simple et universelle écrite par Hendrik Casimir correspond à une idéalisation qui ne décrit pas les expériences réelles. Les effets de la réflexion imparfaite des miroirs, des fluctuations thermiques, de la géométrie plan-sphère utilisée dans les expériences précises sont de mieux en mieux pris en compte. Des progrès sont encore nécessaires en ce qui concerne le rôle des irrégularités des surfaces, rugosité et irrégularités du potentiel (« patch effect »). On présentera l’état actuel de la comparaison entre théorie et expériences pour la force de Casimir entre miroirs métalliques et on insistera sur quelques points qui ne sont pas encore résolus, après des années d’améliorations à la fois théoriques et expérimentales. (Ref: Astrid Lambrecht, Serge Reynaud, Casimir Effect, Theory and Experiments http://arxiv.org/abs/1112.1301v1)

Even though the WIMP framework is a well-motivated scenario that can naturally account for the dark matter, there is currently no evidence that dark matter actually consists of WIMPs. It is important, therefore, not to limit ourselves to WIMP-like solutions to the dark matter problem. In this talk, I will discuss two alternative scenarios that are as simple and predictive as the WIMP one but that can give rise to a very different dark matter phenomenology. In these scenarios, the dark matter interactions are not necessarily of weak-strength and the dark matter mass does not have to be at the GeV-TeV scale. In addition, one of them suggests an intriguing connection between dark matter and inflation.

The importance of using micro- and nano-vectors in drug delivery is a well established issue. Design and preparation of the appropriate vectors for each application requires extensive preliminary studies. These include the search among similar systems, the synthesis of new molecules and the structural characterization of loaded vectors. In fact, trial and error procedures for in vitro and in vivo experiments are costly, time consuming and can imply ethical concerns. Therefore, these procedures should be limited as strictly as possible. In this seminar examples of physico-chemical characterization will be discussed for self assembling structures loaded with anticancer agents, antibacterial drugs or small interfering RNA (siRNA). In particular, liposomes containing boronated componds for Boron Neutron Capture Therapy and Resveratrol against Helicobacter Pylori will be described, along with cationic micelles as possible carriers for siRNA. The information obtained by different methods, such as small angle scattering and magnetic resonance, will be correlated to the association mechanism, the insertion modality and the efficacy of drug delivery.

The glass transition is the dramatic dynamical slowdown one observes when cooling down a liquid or densifying a set of particles into an amorphous state. During this seminar I will tackle first the relation between the very short term dynamics - essentially made of vibrations of the particles around their equilibrium positions - and the long time scale dynamics where dynamical heterogeneities appear and develop on approach to the glass transition. The dynamics of the metastable states is analyzed in two experimental granular systems (grains under cyclic shear or in a fluidized bed) and in simulations of repulsive particles. I will show that in all these systems, the same dynamical facilitation mechanism is at play. Then, I will turn on the relation between dynamics and structure and raise the issue of predictability by using isoconfigurational ensemble techniques in simulations.

We present an introduction to group field theories and tensor models, as a framework for the dynamics of quantum spacetime. They are a generalization of matrix models for 2d quantum gravity, incorporating insights from other approaches like spin foam models and simplicial quantum gravity, as well as tools from non-commutative geometry. We review briefly recent developments, and, if time allows, discuss in more detail some of them.

La physique consiste a identier dans notre environnement des sequences qui se repetent et a essayer de les decrire avec un nombre minimal de lois. Dans ce seminaire, l'environnement sera le Sport et plus particulierement les sports de balles. La premiere partie portera sur l'aerodynamique et les trajectoires et la seconde sur les impacts.

I will discuss the role of pseudo Nambu-Goldstone bosons in particle physics beyond the Standard Model. I will argue that some of these particles are suitable candidates for the dark matter. Their mass and interactions can be connected to the electroweak scale, and in this case the dark matter properties are interlaced with the properties of the Higgs boson. A general introduction will be followed by some phenomenological calculations and some model-building.