Suppression of the superconducting critical current of Nb in bilayers of Nb/SrRuO3

In bilayers consisting of ferromagnetic and superconducting films, the ferromagnetic film in its domain state induces inhomogeneous distribution of magnetic fields in the superconducting film. When the ferromagnetic film has bubble magnetic domains in a labyrinth structure, it has been found that the pinning of the vortices increases; hence, the critical current of the superconducting film becomes larger. Here we study the effect of parallel ferromagnetic domain structure in Nb/SrRuO3 on the critical current of Nb with current flowing perpendicularly to the domains and find that in this case the ferromagnetic domain structure decreases the critical current

Rigidity and non-rigidity results for conformal immersions

In this paper we show a quantitative rigidity result for the minimizer of the Willmore functional among all projective planes in $\mathbb{R}^n$ with $n\ge 4$. We also construct an explicit counterexample to a corresponding rigidity result in codimension one, by showing that an Enneper surface might split-off during a blow-up process. For conformal immersions of spheres with large enough Willmore energies, we construct explicit counterexamples to a quantitative rigidity result and this complements the recently obtained rigidity results in [LaNg13].Comment: Minor modifications, to appear in Adv. Mat

Source Regions of the Type II Radio Burst Observed During a CME-CME Interaction on 2013 May 22

We report on our study of radio source regions during the type II radio burst on 2013 May 22 based on direction finding (DF) analysis of the Wind/WAVES and STEREO/WAVES (SWAVES) radio observations at decameter-hectometric (DH) wavelengths. The type II emission showed an enhancement that coincided with interaction of two coronal mass ejections (CMEs) launched in sequence along closely spaced trajectories. The triangulation of the SWAVES source directions posited the ecliptic projections of the radio sources near the line connecting the Sun and the STEREO-A spacecraft. The WAVES and SWAVES source directions revealed shifts in the latitude of the radio source indicating that the spatial location of the dominant source of the type II emission varies during the CME-CME interaction. The WAVES source directions close to 1 MHz frequencies matched the location of the leading edge of the primary CME seen in the images of the LASCO/C3 coronagraph. This correspondence of spatial locations at both wavelengths confirms that the CME-CME interaction region is the source of the type II enhancement. Comparison of radio and white-light observations also showed that at lower frequencies scattering significantly affects radio wave propagation.Comment: Accepted for publication in Ap

El género Radula Dum. (Radulaceae, Hepaticae) en el noreste de Argentina

En la provincia de Misiones son reconocidas ocho especies de Radula (R. macrostachya Lindenb. & Gott., R. episcia Spruce, R. kegelii Gott. ex Steph., R. ligula Steph., R. aurantii Spruce, R. montana Steph., R. quadrata Gott. y R. voluta Tayl.) y en Buenos Aires dos especies (R. aurantii y R. kegelii). Estas son descriptas, ilustradas, se indica el hábitat y la distribución geográfica mundial. Se aportan claves para la identificación de estas especies y una sinopsis con la posición sistemática de las mismas. R. ligula es trasladada a la sección Marginatae Castle ex Grolle. R. flaccida Lindenb. & Gott. es excluída del área de estudio.Eight species of Radula (R. macrostachya Lindenb. & Gott., R. episcia Spruce, R. kegelii Gott. ex Steph., R. ligula Steph., R. aurantii Spruce, R. montana Steph., R. quadrata Gott. and R. voluta Tayl.) are found in the province of Misiones, and two species (R. aurantii and R. kegelii) in Buenos Aires. These are described and illustrated, and habitat and geographic distribution of the species are indicated. Keys for the identification of these species and a synopsis with their systematic position are provided. R. ligula is transferred to the section Marginatae Castle ex Grolle. R. flaccida Lindenb. & Gott. is excluded from the study area

Las Lejeuneaceae (Hepaticae) de Misiones, Argentina : 6., Lejeunea y Taxilejeunea

Se describen e ilustran las 15 especies de Lejeunea y 3 especies de Taxilejeunea (Lejeuneaceae, subfam. Lejeuneoideae) halladas en Misiones, Argentina: Lejeunea cancellata Nees & Mont., L. filipes Spruce, L. flava (Sw.) Nees, L. geophila Spruce, L. grossitexta (Steph.) E.Reiner & Goda, L. laetevirens Nees & Mont., L. lepida Lindenb. & Gottsche, L. monimiae (Steph.) Steph., L. phyllobola Nees & Mont., L. ptosimophylla C.Massal., L. puiggariana Steph., L. quinqueumbonata Spruce, L. setiloba Spruce, L. tapajosensis Spruce, L. trinitensis Lindenb., Taxilejeunea obtusangula (Spruce) A.Evans, T. pterigonia (Lehm. & Lindenb.) Schiffn. y T. terricola (Spruce) Steph. Se proponen cinco sinónimos nuevos (Lejeunea flava (Sw.) Nees [syn. nov.: L. symphoreta Spruce], L. lepida Lindenb. & Gottsche [syn. nov.: L. cladobola Spruce] y L. phyllobola Nees & Mont. [syn. nov.: L. cephalandra Spruce, L. polycephala Spruce y L. brittoniae (A.Evans) Grolle]), y cuatro lectotipificaciones (L. lepida Lindenb. & Gottsche, L. monimiae (Steph.) Steph., L. phyllobola Nees & Mont. y L. quinqueumbonata Spruce). Claves para la identificación de las especies completan el trabajo.Fifteen species of Lejeunea and three species of Taxilejeunea (Lejeuneaceae, subfam. Lejeuneoideae) occurring in Misiones, Argentina are described and illustrated: Lejeunea cancellata Nees & Mont., L. filipes Spruce, L. flava (Sw.) Nees, L. geophila Spruce, L. grossitexta (Steph.) E.Reiner & Goda, L. laetevirens Nees & Mont., L. lepida Lindenb. & Gottsche, L. monimiae (Steph.) Steph., L. phyllobola Nees & Mont., L. ptosimophylla C.Massal., L. puiggariana Steph., L. quinqueumbonata Spruce, L. setiloba Spruce, L. tapajosensis Spruce, L. trinitensis Lindenb., Taxilejeunea obtusangula (Spruce) A.Evans, T. pterigonia (Lehm. & Lindenb.) Schiffn. and T. terricola (Spruce) Steph. Five new synonyms (Lejeunea flava (Sw.) Nees [syn. nov.: L. symphoreta Spruce], L. lepida Lindenb. & Gottsche [syn. nov.: L. cladobola Spruce] and L. phyllobola Nees & Mont. [syn. nov.: L. cephalandra Spruce, L. polycephala Spruce and L. brittoniae (A.Evans) Grolle]) and four lectotypifications (L. lepida Lindenb. & Gottsche, L. monimiae (Steph.) Steph., L. phyllobola Nees & Mont. and L. quinqueumbonata Spruce) are proposed. Keys for identification of the species are also provided

Infinite compressibility states in the Hierarchical Reference Theory of fluids. II. Numerical evidence

Continuing our investigation into the Hierarchical Reference Theory of fluids for thermodynamic states of infinite isothermal compressibility kappa[T] we now turn to the available numerical evidence to elucidate the character of the partial differential equation: Of the three scenarios identified previously, only the assumption of the equations turning stiff when building up the divergence of kappa[T] allows for a satisfactory interpretation of the data. In addition to the asymptotic regime where the arguments of part I (cond-mat/0308467) directly apply, a similar mechanism is identified that gives rise to transient stiffness at intermediate cutoff for low enough temperature. Heuristic arguments point to a connection between the form of the Fourier transform of the perturbational part of the interaction potential and the cutoff where finite difference approximations of the differential equation cease to be applicable, and they highlight the rather special standing of the hard-core Yukawa potential as regards the severity of the computational difficulties.Comment: J. Stat. Phys., in press. Minor changes to match published versio