23 research outputs found
Anyonic Excitations in Fast Rotating Bose Gases Revisited
The role of anyonic excitations in fast rotating harmonically trapped Bose
gases in a fractional Quantum Hall state is examined. Standard Chern-Simons
anyons as well as "non standard" anyons obtained from a statistical interaction
having Maxwell-Chern-Simons dynamics and suitable non minimal coupling to
matter are considered. Their respective ability to stabilize attractive Bose
gases under fast rotation in the thermodynamical limit is studied. Stability
can be obtained for standard anyons while for non standard anyons, stability
requires that the range of the corresponding statistical interaction does not
exceed the typical wavelenght of the atoms.Comment: 5 pages. Improved version to be published in Phys. Rev. A, including
a physical discussion on relevant interactions and scattering regime together
with implication on the nature of statistical interactio
On the Effective Action of Noncommutative Yang-Mills Theory
We compute here the Yang-Mills effective action on Moyal space by integrating
over the scalar fields in a noncommutative scalar field theory with harmonic
term, minimally coupled to an external gauge potential. We also explain the
special regularisation scheme chosen here and give some links to the Schwinger
parametric representation. Finally, we discuss the results obtained: a
noncommutative possibly renormalisable Yang-Mills theory.Comment: 19 pages, 6 figures. At the occasion of the "International Conference
on Noncommutative Geometry and Physics", April 2007, Orsay (France). To
appear in J. Phys. Conf. Se
Vacuum configurations for renormalizable non-commutative scalar models
In this paper we find non-trivial vacuum states for the renormalizable
non-commutative model. An associated linear sigma model is then
considered. We further investigate the corresponding spontaneous symmetry
breaking.Comment: 17 page
One-loop Beta Functions for the Orientable Non-commutative Gross-Neveu Model
We compute at the one-loop order the beta-functions for a renormalisable
non-commutative analog of the Gross Neveu model defined on the Moyal plane. The
calculation is performed within the so called x-space formalism. We find that
this non-commutative field theory exhibits asymptotic freedom for any number of
colors. The beta-function for the non-commutative counterpart of the Thirring
model is found to be non vanishing.Comment: 16 pages, 9 figure
First case of childhood Takayasu arteritis with renal artery aneurysms
Takayasu arteritis is a large vessel systemic granulomatous vasculitis characterized by stenosis or obliteration of large and medium sized arteries. It commonly involves elastic arteries such as the aorta and its main branches. Renal artery involvement is rare and has not been reported in a child. We report a 12-year-old boy with Takayasu arteritis who developed severe hypertension, proteinuria, microscopic hematuria and renal dysfunction. Conventional angiography demonstrated aneurysms of both renal arteries and multiple microaneurysms of the superior mesenteric artery. This case report illustrates that the children with Takayasu arteritis can develop renal involvement resulting in hematuria, proteinuria and even renal failure
On the vacuum states for noncommutative gauge theory
Candidates for renormalisable gauge theory models on Moyal spaces constructed
recently have non trivial vacua. We show that these models support vacuum
states that are invariant under both global rotations and symplectic
isomorphisms which form a global symmetry group for the action. We compute the
explicit expression in the position space for these vacuum configurations in
two and four dimensions.Comment: 20 page
Extended Generation Profile - E.B.I.C. Model
We have developed a model for the calculation of the induced current due to an electron beam with an extended profile. As well as the number of absorbed and diffuse electrons as a function of the depth, the generation profile takes into account the lateral diffusion and the effect of defects, dislocations and recombination surfaces. The expression from the Electron Beam Induced Current (EBIC) is obtained by solving the continuity equation in permanent regime by the Green function method. In the case of a Schottky diode Au/InP, obtained by ionic scattering followed by a quick thermal treatment, the induced current profile is compared to the theoretical profiles whose analytical expressions are given by Van Roosbroeck and Bresse. The experimental current profile, measured by S.E.M provided us with the calculation of the diffusion length of the minority carriers,  m. The theoretical curve obtained from the proposed model is in good agreement with the experimental one for a surface recombination velocity of  cm s. Our results are found to be consistent with those obtained by other experimental techniques on the same samples.Nous avons développé un modèle de calcul du courant induit par un faisceau
d'électrons avec un profil de génération élargi. Le profil de
génération tient compte, en plus du nombre d'électrons absorbés et du
nombre d'électrons diffusés en fonction de la profondeur, de la diffusion
latérale (en prenant en considération la diffusion angulaire), de l'effet
des défauts, des dislocations et de la recombinaison à la surface.
L'expression analytique du courant induit E.B.I.C est déterminée par
résolution de l'équation de continuité en régime permanent par la
méthode des fonctions de Green. Le profil de courant induit obtenu dans le cas
d'une diode Schottky Au/InP dopé p et fabriqué par implantation suivit d'un
recuit, est comparé au profil de courant théorique dont l'expression
analytique est explicité par Van Roosbroeck et Bresse. Le profil de courant
expérimental, mesuré par un microscope électronique à balayage, nous a
permis de calculer la longueur de diffusion des porteurs minoritaires  m. La courbe théorique, tracée à partir du modèle proposé, est en bon accord avec la courbe expérimental pour une vitesse de recombinaison à la surface de  cm s. Ces résultats sont conformes avec ceux obtenus par d'autres techniques
expérimentales sur les mêmes échantillons