132,871 research outputs found
Ángela Hernández Núñez, Ventuno aforismi
No full text21 aforismos de la poeta dominicana Ángela Hernández Núñez (1954), sacados del libro “Breve filosofía para el amanecer” (2024), traducidos al italiano por Danilo Manera, con una nota crítica
Uno sguardo femminile tra devianza e fiducia
No full textIntroduzione e commento critico ai racconti della scrittrice dominicana Ángela Hernández Núñez (1954), posposto a una antologia in italiano curata da Danilo Manera.Comentario crítico a una antología de cuentos, traducidos al italiano, de la escritora dominicana Ángela Hernández Núñez (1954), preparada por Danilo Manera.
Una brecha en el agua
No full textStudio introduttivo alla raccolta di racconti scelti della scrittrice dominicana Ángela Hernández Núñez (1954)
An axiomatic approach to supermanifolds
No full text"The authors reconsider M. J. Rothstein’s axiomatization [Trans. Amer. Math. Soc. 297 (1986), no. 1, 159–180; MR0849473 (87m:58015)] of supermanifolds in the light of its giving a much wider category of supermanifolds than the Berezin-Leıtes-Kostant category of supermanifolds for a given choice of the Banach algebra occurring as the base. They show that by adding an axiom asserting the completeness of the rings of sections of structure sheaves this difficulty can be removed. Moreover, when the base algebra is a finite-dimensional exterior algebra, then the category of Rothstein supermanifolds is equivalent to the category of G-supermanifolds introduced by Bartocci, Bruzzo and Hernández Ruipérez [The geometry of supermanifolds, Kluwer Dordrecht, 1991]." J. S. Joel, MR1153267 (92k:58015
Mutual friction and vortex Hall angle in a strongly interacting Fermi superfluid
No full textWe investigate the two-dimensional motion of a single vortex orbiting a pinned anti-vortex in a unitary Fermi superfluid. By analyzing its trajectory, we measure the yet-unknown longitudinal and transverse mutual friction coefficients, which quantify the vortex-mediated coupling between the normal and superfluid components. Both coefficients increase while approaching the superfluid transition. They provide access to the vortex Hall angle, which is linked to the relaxation time of the localized quasiparticles occupying Andreev bound states within the vortex core, and to the vortex Reynolds number Re alpha associated with the transition from laminar to quantum turbulent flows. We compare our results with numerical simulations and an analytic model originally formulated for superfluid 3He, finding good agreement. Our work suggests that vortex dynamics in unitary Fermi superfluids is essentially affected by the interplay between delocalized thermal excitations and vortex-bound quasiparticles. Further, it provides a novel testbed for studying vortex dynamics at finite temperatures
Connecting shear-flow and vortex array instabilities in annular atomic superfluids
No full textAt the interface between two fluid layers in relative motion, infinitesimal
fluctuations can be exponentially amplified, inducing vorticity and the
breakdown of the laminar flow. This process, known as the Kelvin-Helmholtz
instability, is responsible for many familiar phenomena observed in the
atmosphere and in the oceans, as well as in astrophysical objects, being known
as one of the paradigmatic routes to turbulence in fluid mechanics. While
shear-flow instabilities in classical fluids have been extensively observed in
various contexts, controlled experiments in the presence of quantized
circulation are comparatively very few. Here, we engineer two counter-rotating
atomic superflows, a configuration that in classical inviscid fluids is
unstable via the Kelvin-Helmholtz instability. We observe how the contact
interface, i.e. the shear layer, develops into an ordered circular array of
quantized vortices, which loses stability and rolls up into vortex clusters. We
extract the instability growth rates and find that they obey the same scaling
relations across different superfluid regimes, ranging from weakly-interacting
bosonic to strongly-correlated fermionic pair condensates. The measured
scalings, reproduced by numerical simulations and well described by a
microscopic point-vortex model, are consistent with the classical hydrodynamic
Kelvin-Helmholtz instability of a finite-width shear layer. Our results
establish interesting connections between vortex arrays and shear-flow
instabilities, suggesting a possible interpretation of the observed quantized
vortex dynamics as a manifestation of the underlying unstable flow. Moreover,
they open the way for exploring a wealth of out-of-equilibrium phenomena, from
vortex-matter phase transitions to the spontaneous emergence and decay of
two-dimensional quantum turbulence
Correction: Allogeneic haematopoietic cell transplantation for myelofibrosis: proposed definitions and management strategies for graft failure, poor graft function and relapse: best practice recommendations of the EBMT Chronic Malignancies Working Party (Leukemia, (2021), 35, 9, (2445-2459), 10.1038/s41375-021-01294-2)
No full textDuring the Editorial process, the author name of Juan Carlos Hernández-Boluda to Hernández Boluda. The original article was updated to correct this
Products and vector bundles in the category of G-supermanifolds
No full textIn the present paper we introduce the concept of a product of G-supermanifolds and develop the concept of a (super)vector bundle. In both cases, the definition of the structure sheaf of the total space occurs to be nontrivial
Structural, vibrational and thermodynamic properties of Mg2SiO4 and MgSiO3 minerals from first-principles simulations
No full textFourier-Mukai transform and index theory
No full textGiven a submersive morphism of complex manifolds f: X --> Y, and a complex vector bundle E on X, there is a relationship between the higher direct images of the sheaf of holomorphic sections of E and the index of the relative Dolbeault compplex twisted by E. This relationship allows one to yield a global and simple proof of the equivalence between the Mukai transform of stable vector bundles on a torus T of complex dimension 2 and the Nahm transform of instantons. We also offer a proof of Mukai's inversion theorem which circumvents the use of derived categories by introducing spectral sequences of sheaves on T (this is related to Donaldson and Kronheimer's proof, but is automatically global and somehow simpler). The general framework developed in the first part of this papare may be applied to the study of the Mukai transform for more general varieties
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