Superlattice switching from parametric instabilities in a driven-dissipative BEC in a cavity

We numerically obtain the full time-evolution of a parametrically-driven dissipative Bose-Einstein condensate in an optical cavity and investigate the implications of driving for the phase diagram. Beyond the normal and superradiant phases, a third nonequilibrium phase emerges as a manybody parametric resonance. This dynamical normal phase switches between two symmetry-broken superradiant configurations. The switching implies a breakdown of the system's mapping to the Dicke model. Unlike the other phases, the dynamical normal phase shows features of nonintegrability and thermalization.Comment: 5 pages, 3 figure

Formal Analysis and Estimation of Chance in Datasets Based on Their Properties

Machine learning research, particularly in genomics, is often based on wide shaped datasets, i.e. datasets having a large number of features, but a small number of samples. Such configurations raise the possibility of chance influence (the increase of measured accuracy due to chance correlations) on the learning process and the evaluation results. Prior research underlined the problem of generalization of models obtained based on such data. In this paper, we investigate the influence of chance on prediction and show its significant effects on wide shaped datasets. First, we empirically demonstrate how significant the influence of chance in such datasets is by showing that prediction models trained on thousands of randomly generated datasets can achieve high accuracy. This is the case even when using cross-validation. We then provide a formal analysis of chance influence and design formal chance influence estimators based on the dataset parameters, namely its sample size, the number of features, the number of classes and the class distribution. Finally, we provide an in-depth discussion of the formal analysis including applications of the findings and recommendations on chance influence mitigation

Optimized observable readout from single-shot images of ultracold atoms via machine learning

Single-shot images are the standard readout of experiments with ultracold atoms, the imperfect reflection of their many-body physics. The efficient extraction of observables from single-shot images is thus crucial. Here we demonstrate how artificial neural networks can optimize this extraction. In contrast to standard averaging approaches, machine learning allows both one- and two-particle densities to be accurately obtained from a drastically reduced number of single-shot images. Quantum fluctuations and correlations are directly harnessed to obtain physical observables for bosons in a tilted double-well potential at an extreme accuracy. Strikingly, machine learning also enables a reliable extraction of momentum-space observables from real-space single-shot images and vice versa. With this technique, the reconfiguration of the experimental setup between in situ and time-of-flight imaging is required only once to obtain training data, thus potentially granting an outstanding reduction in resources

Many-body physics in two-component Bose-Einstein condensates in a cavity: fragmented superradiance and polarization

We consider laser-pumped one-dimensional two-component bosons in a parabolic trap embedded in a high-finesse optical cavity. Above a threshold pump power, the photons that populate the cavity modify the effective atom trap and mediate a coupling between the two components of the Bose-Einstein condensate. We calculate the ground state of the laser-pumped system and find different stages of self-organization depending on the power of the laser. The modified potential and the laser-mediated coupling between the atomic components give rise to rich many-body physics: an increase of the pump power triggers a self-organization of the atoms while an even larger pump power causes correlations between the self-organized atoms -- the BEC becomes fragmented and the reduced density matrix acquires multiple macroscopic eigenvalues. In this fragmented superradiant state, the atoms can no longer be described as two-level systems and the mapping of the system to the Dicke model breaks down.Comment: 8 pages, 3 figures, software available at http://ultracold.or

Optically levitated nanoparticle as a model system for stochastic bistable dynamics

Nano-mechanical resonators have gained an increasing importance in nanotechnology owing to their contributions to both fundamental and applied science. Yet, their small dimensions and mass raises some challenges as their dynamics gets dominated by nonlinearities that degrade their performance, for instance in sensing applications. Here, we report on the precise control of the nonlinear and stochastic bistable dynamics of a levitated nanoparticle in high vacuum. We demonstrate how it can lead to efficient signal amplification schemes, including stochastic resonance. This work contributes to showing the use of levitated nanoparticles as a model system for stochastic bistable dynamics, with applications to a wide variety of fields.inancial support from the ERC- QnanoMECA (Grant No. 64790), the Spanish Ministry of Economy and Competitiveness, under grant FIS2016-80293-R and through the ‘Severo Ochoa’ Programme for Centres of Excellence in R&D (SEV-2015-0522), Fundació Privada CELLEX and from the CERCA Programme/Generalitat de Catalunya. J.G. has been supported by H2020-MSCA-IF-2014 under REA grant Agreement No. 655369. L.R. acknowledges support from an ETH Marie Curie Cofund Fellowship

Análise da adequação orçamentária e financeira da Medida Provisória nº 661, de 2 de dezembro de 2014

Interessada: Comissão Mista encarregada de emitir parecer sobre a referida Medida Provisória.Subsídios para a apreciação da Medida Provisória que Autoriza a União a conceder crédito ao Banco Nacional de Desenvolvimento Econômico e Social - BNDES e a destinar superávit financeiro das fontes de recursos existentes no Tesouro Nacional à cobertura de despesas primárias obrigatórias.

Adrianallarin's Blog: De Allá para acá y viceversa

Por que debo justificarme paso a contarles el porque, el para que, y el como de este blog. Se creó por expresa solicitud del Taller de Producción del Posgrado en Producción y Análisis en Textos Críticos I.U.N.A.. La finalidad del mismo es dar a conocer y difundir mi obra, algunos de mis escritos personales y textos de las críticas que realicé a otros artistas y críticas realizadas a mi obra, por otros. Escogí el formato de “Paginas” y no de “Entradas”, dado que el dinamismo del Blog pretendo darlo por el ida y vuelta con los visitantes y no por la periodicidad de los posteos. Así mismo me lo requeria la variedad de formas de lo presentado, respecto a los textos e imágenes expuestos aquí. En cuanto a la plantilla utilizada, tuve en cuenta sus posibilidades estéticas. De lo antes comentado se desprende que cumplirá con una doble función, la de difundir mi trabajo como artista y profesional, y la de abrir un espacio de debate (dificil de lograr si no por este medio) partiendo de mis autocríticas en busca de una respuesta de los visitantes

Análise da adequação orçamentária e financeira da Medida Provisória nº 815, de 29 de dezembro de 2017

Subsídios para a apreciação da Medida Provisória que “Dispõe sobre a prestação de apoio financeiro pela União aos entes federativos que recebem o Fundo de Participação dos Municípios - FPM, no exercício de 2018”.Vincenzo Papariello Junio

Análise da adequação orçamentária e financeira da Medida Provisória nº 648, de 3 de junho de 2014

Interessada: Comissão Mista encarregada de emitir parecer sobre a referida Medida Provisória.Análise da Medida Provisória que altera a Lei nº 4.117, de 27 de agosto de 1962, e dispõe sobre a flexibilização do horário de transmissão do programa oficial de informações dos Poderes da República ( Voz do Brasil) , durante a Copa do Mundo FIFA 2014.Vincenzo Papariello Júnio