Vortices in quantum droplets: Analogies between boson and fermion systems

The main theme of this review is the many-body physics of vortices in quantum droplets of bosons or fermions, in the limit of small particle numbers. Systems of interest include cold atoms in traps as well as electrons confined in quantum dots. When set to rotate, these in principle very different quantum systems show remarkable analogies. The topics reviewed include the structure of the finite rotating many-body state, universality of vortex formation and localization of vortices in both bosonic and fermionic systems, and the emergence of particle-vortex composites in the quantum Hall regime. An overview of the computational many-body techniques sets focus on the configuration interaction and density-functional methods. Studies of quantum droplets with one or several particle components, where vortices as well as coreless vortices may occur, are reviewed, and theoretical as well as experimental challenges are discussed.Comment: Review article, 53 pages, 53 figure

Chemical equilibrium study in nucleus-nucleus collisions at relativistic energies

We present a detailed study of chemical freeze-out in nucleus-nucleus collisions at beam energies of 11.6, 30, 40, 80 and 158A GeV. By analyzing hadronic multiplicities within the statistical hadronization approach, we have studied the strangeness production as a function of centre of mass energy and of the parameters of the source. We have tested and compared different versions of the statistical model, with special emphasis on possible explanations of the observed strangeness hadronic phase space under-saturation. We show that, in this energy range, the use of hadron yields at midrapidity instead of in full phase space artificially enhances strangeness production and could lead to incorrect conclusions as far as the occurrence of full chemical equilibrium is concerned. In addition to the basic model with an extra strange quark non-equilibrium parameter, we have tested three more schemes: a two-component model superimposing hadrons coming out of single nucleon-nucleon interactions to those emerging from large fireballs at equilibrium, a model with local strangeness neutrality and a model with strange and light quark non-equilibrium parameters. The behaviour of the source parameters as a function of colliding system and collision energy is studied. The description of strangeness production entails a non-monotonic energy dependence of strangeness saturation parameter gamma_S with a maximum around 30A GeV. We also present predictions of the production rates of still unmeasured hadrons including the newly discovered Theta^+(1540) pentaquark baryon.Comment: 36 pages, 14 figures. Revised version published in Phys. Rev. C: title changed, one paragraph added in section 2, other typos correcte

Superconducting MoSi nanowires

We have fabricated disordered superconducting nanowires of molybdenium silicide. A molybdenium nanowire is first deposited on top of silicon, and the alloy is formed by rapid thermal annealing. The method allows tuning of the crystal growth to optimise, e.g., the resistivity of the alloy for potential applications in quantum phase slip devices and superconducting nanowire single-photon detectors. The wires have effective diameters from 42 to 79 nm, enabling the observation of crossover from conventional superconductivity to regimes affected by thermal and quantum fluctuations. In the smallest diameter wire and at temperatures well below the superconducting critical temperature, we observe residual resistance and negative magnetoresistance, which can be considered as fingerprints of quantum phase slips

Media representations of female leaders on Instagram

Abstract. Media occupies large amount of our time and attention every day. For that reason, every one of us is under the influence of media representations. Media representations but also media representations of female leaders are largely studied themes. Regardless of that, social media representations have remained understudied, and within the context of leadership there is a research gap. This study elaborates how leading business media houses, The Economist and Forbes, represent female leaders on their social media accounts. Social media representations are studied by social media critical discourse analysis, which focuses on the phenomenon through the critical approach also considering the multimodality of the representations. The empirical research material includes 44 Instagram postings of female leaders in 2022 on the profiles of The Economist and Forbes. This material is encoded separately regarding the visual and verbal element of the representations, but after that considered together in the data analysis to conduct the multimodal research of representations. The research discovered that social media representations of female leaders have a more neutral approach than traditional media does. With a brief view, the representations represent leaders in a neutral picture settings and professional text. However, the power relations between the viewer and the subject of the representations are diminished by close-up portraits within the shared level, so the leader is not represented being in a higher position than the viewer. Mainly neutral background of the pictures draws the attention towards the leader, but at the same time she is not represented in her working settings, which decreases the power relations. In verbal element female leaders are represented by highlighting her name, title, and actions. The gender of the leader is mentioned regularly and the age of hers is brought into a representation especially when the leader is relatively young or old. The majority of the representations express the name and the title of the leader already within the headline, but minority of the representations do not consider these as important factors. From social media representations can already be recognized discourses of helplessness, problem, and superwomen besides duality setting femininity versus masculinity. Together these multimodal social media representations send mixed signals for the consumer, which challenges individual’s meaning construction. Consequently, based on the more neutral representations of social media, this attitude needs to be transformed into traditional media’s representations in the future. These social media representations characterize the development towards more gender-neutral media representations of leadership and leaders

S-Matrix Formulation of Mesoscopic Systems and Evanescent Modes

The Landauer-Butikker formalism is an important formalism to study mesoscopic systems. Its validity for linear transport is well established theoretically as well as experimentally. Akkermans et al [Phys. Rev. Lett. {\bf 66}, 76 (1991)] had shown that the formalism can be extended to study thermodynamic properties like persistent currents. It was earlier verified for simple one dimensional systems. We study this formula very carefully and conclude that it requires reinterpretation in quasi one dimension. This is essentially because of the presence of evanescent modes in quasi one dimension.Comment: non

Effective UV surface albedo of seasonally snow-covered lands

International audienceAt ultraviolet wavelengths the albedo of most natural surfaces is small with the striking exception of snow and ice. Therefore, snow cover is a major challenge for various applications based on radiative transfer modelling. The aim of this work was to determine the characteristic effective UV range surface albedo of various land cover types when covered by snow. First we selected 1 by 1 degree sample regions that met three criteria: the sample region contained dominantly subpixels of only one land cover type according to the 8 km global land cover classification product from the University of Maryland; the average slope of the sample region was less than 2 degrees according to the USGS's HYDRO1K slope data; the sample region had snow cover in March according to the NSIDC Northern Hemisphere weekly snow cover data. Next we generated 1 by 1 degree gridded 360 nm surface albedo data from the Nimbus-7 TOMS Lambertian equivalent reflectivity data, and used them to construct characteristic effective surface albedo distributions for each land cover type. The resulting distributions showed that each land cover type experiences a characteristic range of surface albedo values when covered by snow. The result is explained by the vegetation that extends upward beyond the snow cover and masks the bright snow covered surface

Suffering and Soul-Making in Disney/Pixar’s Inside Out

John Hick (1922-2012) was an extremely influential philosopher of religion who wrote ground-breaking essays in the areas of religious epistemology, religious pluralism, and the problem of evil. With specific reference to the latter, in his book Evil and the God of Love(1966), Hick devised what has come to be known as the “soul-making theodicy” – in essence, Hick argues that one of the reasons God allows so much apparently pointless suffering in the world is because it is an essential aspect of advancing our moral and spiritual education. Although perhaps an unlikely venue, I will argue that Disney/Pixar’s 2015 animated film Inside Out can help us see how suffering serves the role Hick attributes to it. One of the film’s many messages is that suffering not only forms the foundation for the cultivation of compassion and human intimacy, but is an indispensable aspect of attaining a healthy moral, spiritual, intellectual, and mental maturity. While there is little to suggest that Inside Out \u27s director Peter Docter had theodicies specifically in mind while making the film (though he has admitted that his Christian views have infused his films in the past), the fact that we can appeal to philosophy and theology to further our understanding of the film\u27s themes illustrates the connection these fields of study can have to (secular) popular culture, and that theists and non-theists can find common language to talk about the perennial philosophical issues that permeate human existence

Chemical equilibrium study at SPS 158A GeV

A detailed study of chemical freeze-out in nucleus-nucleus collisions at beam energy 158A GeV is presented. By analyzing hadronic multiplicities within the statistical hadronization approach, the chemical equilibration of p-p, C-C, Si-Si and Pb-Pb systems is studied as a function of the number of participating nucleons in the system. Additionally, Two Component statistical hadronization model is applied to the data and is found to be able to explain the observed strangeness hadronic phase space under-saturation.Comment: 4 pages, 3 figures to appear in the proceedings of the ''Strangeness in Quark Matter 2004'' conferenc