Universal self-similar attractor in the bending-driven levelling of thin viscous films

We study theoretically and numerically the bending-driven levelling of thin viscous films within the lubrication approximation. We derive Green’s function of the linearized thin-film equation and further show that it represents a universal self-similar attractor at long times. As such, the rescaled perturbation of the film profile converges in time towards the rescaled Green’s function, for any summable initial perturbation profile. In addition, for stepped axisymmetric initial conditions, we demonstrate the existence of another, short-term and one-dimensional-like self-similar regime. We also characterize the convergence time towards the long-term universal attractor in terms of the relevant physical and geometrical parameters, and provide the local hydrodynamic fields and global elastic energy in the universal regime as functions of time. Finally, we extend our analysis to the nonlinear thin-film equation through numerical simulations.

Coulomb Blockade Thermometry Beyond the Universal Regime

The charge localization of single electrons on mesoscopic metallic islands leads to a suppression of the electrical current, known as the Coulomb blockade. When this correction is small, it enables primary electron thermometry, as it was first demonstrated by Pekola et al. (Phys Rev Lett 73:2903, 1994). However, in the low temperature limit, random charge offsets influence the conductance and limit the universal behavior of a single metallic island. In this work, we numerically investigate the conductance of a junction array and demonstrate the extension of the primary regime for large arrays, even when the variations in the device parameters are taken into account. We find that our simulations agree well with measured conductance traces in the submillikelvin electron temperature regime.

Ice fabrics in natural flows: moving away from pure and simple shear

<div>Antarctic ice flow shows deviation from the deformation regimes of pure and simple shear. By analysing the vorticity number from surface velocity data it is found that approximately 80% of the flow is outside these regimes. These deformations are both between pure and simple shear, as well as highly rotational, highlighting the need for fabric predictions away from the commonly studied regimes of pure and simple shear. </div><div>We use the numerical scheme SpecCAF, which has been shown to accurately reproduce experimentally observed fabrics with no free parameters, to study ice fabrics in such general deformations. By exploring the parameter space of temperature and vorticity number, we present a definitive classification of fabrics patterns which arise, and construct a universal regime diagram for ice fabrics under general two-dimensional deformation. We find that intermediate deformations see a smooth transition between a cone-shape fabric and a secondary cluster. We present the first investigation of the fabrics produced in highly rotational deformations, which produce a weak girdle fabric with the axis aligned to the vorticity axis. We also show that across deformation and temperature space fabrics only reach a true steady-state above strains of 200%, and there is significant variation in this across the parameter space.  </div>

A ESCOLA COMO ESPAÇO DA EDUCAÇÃO PARA A CIDADANIA: UMA ANÁLISE DA PROPOSTA DE NORBERTO BOBBIO

Norberto Bobbio vê no estado democrático o único meio capaz de colocar as pessoas em igualdade de condições e de garantir a existência e continuidade das liberdades fundamentais, refletindo sobre o contraste que existe entre os ideais democráticos e a “democracia real”. Daí a necessidade de concentrar a discussão entre o que foi prometido e o efetivamente praticado, ou seja, tentar um prognóstico sobre as “promessas” não cumpridas. Para o autor, o termo democracia apresentar-se-ia sob dois aspectos: primeiro como “um conjunto de instituições ou técnicas de governo”, sendo essas o “sufrágio universal, regime parlamentar, reconhecimento dos direitos civis, princípios da maioria”; em segundo lugar, como “um certo ideal a ser perseguido”. Assim, a democracia define-se como técnica de governo e meio empregado para organizar a sociedade e, como ideal, propõe a busca por um fim desejado, i.e., a igualdade entre os homens, somente alcançada pela educação.

TRANSPORT THROUGH INTERACTING AHARONOV–BOHM–CASHER INTERFEROMETERS

We investigate the transport properties of an interacting ring threaded by a magnetic flux and with Rashba spin-orbit coupling, based on a recently developed functional renormalized group technique. In the calculations of the electronic transport processes, the Coloumb On-site interactions are taken into account. For an interacting ring connected to two leads, we find that (i) for ΦAC = 0, the behavior of transmission zero at ΦAB = π is generic for the universal regime; (ii) for certain ΦAC and ΦAB, one can use the mesoscopic ring as spin filter even in the presence of the local interaction in the ring.

Resummation and the semiclassical theory of spectral statistics

We address the question as to why, in the semiclassical limit, classically chaotic systems generically exhibit universal quantum spectral statistics coincident with those of random-matrix theory. To do so, we use a semiclassical resummation formalism that explicitly preserves the unitarity of the quantum time evolution by incorporating duality relations between short and long classical orbits. This allows us to obtain both the non-oscillatory and the oscillatory contributions to spectral correlation functions within a unified framework, thus overcoming a significant problem in previous approaches. In addition, our results extend beyond the universal regime to describe the system-specific approach to the semiclassical limit.

Leo Strauss's Indictment of Christain Philosophy

Leo Strauss's writings reveal a subtle but consistent set of accusations against the influence of Christian thinkers on political philosophy. These accusations may be summarized in three charges. First, the attempt by Aquinas and other Christian scholastics to synthesize faith and reason led later philosophers to eschew prudence in favor of a humane project to employ science to transform political life. The result was the destruction of the modus vivendi, safeguarded by classical political philosophy, between pious citizens and diffident but inwardly free philosophers. Second, the rationalization of political life implies that a universal regime is possible. But, unless all men become philosophers, this universal regime can be only a universal tyranny, ruled by means of perverted faith in the guise of a final philosophy. Third, Christian thinkers must bear ultimate responsibility for precipitating the early modern rejection of classical political philosophy. Without the Christian appropriation of Aristotle, there might never have been a Machiavelli or a Hobbes.