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Since the expansion of the universe was first established by Edwin Hubble and Georges Lemaître about a century ago, the Hubble constant H0 which measures its rate has been of great interest to astronomers. Besides being interesting in its own right, few properties of the universe can be deduced without it. In the last decade, a significant gap has emerged between different methods of measuring it, some anchored in the nearby universe, others at cosmological distances. The SH0ES team has found H0=73.2±1.3kms-1Mpc-1 locally, whereas the value found for the early universe by the Planck Collaboration is H0=67.4±0.5kms-1Mpc-1 from measurements of the cosmic microwave background. Is this gap a sign that the well-established ΛCDM cosmological model is somehow incomplete? Or are there unknown systematics? And more practically, how should humble astronomers pick between competing claims if they need to assume a value for a certain purpose? In this article, we review results and what changes to the cosmological model could be needed to accommodate them all. For astronomers in a hurry, we provide a buyer’s guide to the results, and make recommendations.

We present an approach for using machine learning to automatically discover the governing equations and unknown properties (in this case, masses) of real physical systems from observations. We train a ‘graph neural network’ to simulate the dynamics of our Solar System’s Sun, planets, and large moons from 30 years of trajectory data. We then use symbolic regression to correctly infer an analytical expression for the force law implicitly learned by the neural network, which our results showed is equivalent to Newton’s law of gravitation. The key assumptions our method makes are translational and rotational equivariance, and Newton’s second and third laws of motion. It did not, however, require any assumptions about the masses of planets and moons or physical constants, but nonetheless, they, too, were accurately inferred with our method. Naturally, the classical law of gravitation has been known since Isaac Newton, but our results demonstrate that our method can discover unknown laws and hidden properties from observed data.

Simulation-based inference (SBI) is rapidly establishing itself as a standard machine learning technique for analyzing data in cosmological surveys. Despite continual improvements to the quality of density estimation by learned models, applications of such techniques to real data are entirely reliant on the generalization power of neural networks far outside the training distribution, which is mostly unconstrained. Due to the imperfections in scientist-created simulations, and the large computational expense of generating all possible parameter combinations, SBI methods in cosmology are vulnerable to such generalization issues. Here, we discuss the effects of both issues, and show how using a Bayesian neural network framework for training SBI can mitigate biases, and result in more reliable inference outside the training set. We introduce cosmoSWAG , the first application of stochastic weight averaging to cosmology, and apply it to SBI trained for inference on the cosmic microwave background.

In this work, we utilise a combination of theory, computation and experiments to understand the early events related to the nucleation of Ag filaments on α-Ag 2 WO 4 crystals, which is driven by an accelerated electron beam from an electron microscope under high vacuum . The growth process and the chemical composition and elemental distribution in these filaments were analysed in depth at the nanoscale level using TEM, HAADF, EDS and XPS; the structural and electronic aspects were systematically studied in using first-principles electronic structure theory within QTAIM framework. The Ag nucleation and formation on α-Ag 2 WO 4 is a result of the order/disorder effects generated in the crystal by the electron-beam irradiation. Both experimental and theoretical results show that this behavior is associated with structural and electronic changes of the [AgO 2 ] and [AgO 4 ] clusters and, to a minor extent, to the [WO 6 ] cluster; these clusters collectively represent the constituent building blocks of α-Ag 2 WO 4 .

A visibilidade e a valorização dos negros na cultura gaúcha são reivindicadas em Bandone do Caverá (2008), poemeto escrito aos moldes da tradição gauchesca que retoma a vida de Adauto Costa Ferreira, músico residente na região da campanha, no interior de Rosário do Sul/RS. O autor, Oliveira Silveira (1941-2009), propõe, em seu último livro publicado, um itinerário à memória e à história oral das lembranças da infância a partir da música como elemento agregador da família e da comunidade. O objetivo deste artigo consiste em apresentar uma análise de Bandone do Caverá pela composição do protagonista como referência positiva de homem, negro e gaúcho a propósito de um tempo que não existe mais. Para a realização dessa leitura, consideramos principalmente os estudos sobre a literatura afro-brasileira propostas por Cuti (2010), Miriam Alves (2010) e Zilá Bernd (2011). Observamos que o eu lírico recorre à história ancestral como elemento agregador da cultura gaúcha, resultando na homenagem a uma figura ligada à memória afetiva e à identidade étnica do autor. The visibility and valorization of black people in the southern Brazilian culture are vindicated in Bandone do Caverá (2008), a poem written in the pattern of the pampa tradition which take the life of Adauto Costa Ferreira, a musician that lived in the rural region of Rosário do Sul/RS. The author, Oliveira Silveira (1941-2009), purpose, in his last published work, an itinerary to the memory and oral history of remembrances of childhood from music as an aggregator element of family and community. The aim of this paper is to present an analysis of Bandone do Caverá by the composition of the protagonist as a positive reference of man, black and gaucho by means of a time that does not exist anymore. To do this reading, we consider mainly the studies of afro-brazilian literature by Cuti (2010), Miriam Alves (2010), Zilá Bernd (2011). We noted that the lyric speaker uses the ancestral history as an aggregator element of the southern culture, resulting in a homage to a figure related to the emotional memory and ethical identity of the author.

Kikuchi-Fujimoto disease, or histiocytic necrotizing lymphadenitis, is an infrequent idiopathic disorder. It has been associated with autoimmune disorders, of which systemic lupus erythematosus is the most outstanding. The basis of its diagnosis relies on the histological examination of lymph nodes, which typically reveals necrosis surrounded by histiocytes with crescentic nucleus, immunoblasts and plasma cells, and absence of neutrophils. We report the case of a 27-year-old Argentinian female patient without any relevant past medical history to demonstrate the correlation between Kikuchi-Fujimoto disease and systemic lupus erythematosus.

Observations of a stellar occultation by (10199) Chariklo, a minor body that orbits the Sun between Jupiter and Neptune, reveal that it has a ring system, a property previously observed only for the four giant planets of the Solar System. Tiny Chariklo has its own ring system Observations of a stellar occultation by (10199) Chariklo, a Centaur-class outer-system asteroid orbiting between Saturn and Uranus, reveal that it has a ring system, a feature previously observed only for the four giant planets. Chariklo, with a diameter of about 250 km, has two narrow and dense rings separated by a small gap, probably due to the presence of a (yet-to-be-found) kilometre-sized satellite. The discovery of these rings raises questions about the formation and dynamical evolution of planetary rings. For one thing, it seems likely that planetary rings are much more common than previously thought. Hitherto, rings have been found exclusively around the four giant planets in the Solar System 1 . Rings are natural laboratories in which to study dynamical processes analogous to those that take place during the formation of planetary systems and galaxies. Their presence also tells us about the origin and evolution of the body they encircle. Here we report observations of a multichord stellar occultation that revealed the presence of a ring system around (10199) Chariklo, which is a Centaur—that is, one of a class of small objects orbiting primarily between Jupiter and Neptune—with an equivalent radius of 124   9 kilometres (ref. 2 ). There are two dense rings, with respective widths of about 7 and 3 kilometres, optical depths of 0.4 and 0.06, and orbital radii of 391 and 405 kilometres. The present orientation of the ring is consistent with an edge-on geometry in 2008, which provides a simple explanation for the dimming 3 of the Chariklo system between 1997 and 2008, and for the gradual disappearance of ice and other absorption features in its spectrum over the same period 4 , 5 . This implies that the rings are partly composed of water ice. They may be the remnants of a debris disk, possibly confined by embedded, kilometre-sized satellites.

The standard Λ CDM cosmological model predicts the presence of cold dark matter, with the current accelerated expansion of the Universe driven by dark energy. This model has recently come under scrutiny because of tensions in measurements of the expansion and growth histories of the Universe, parameterized using H 0 and S 8 . The three-dimensional clustering of galaxies encodes key cosmological information that addresses these tensions. Here we present a set of cosmological constraints using simulation-based inference that exploits additional non-Gaussian information on nonlinear scales from galaxy clustering, inaccessible with current analyses. We analyse a subset of the Baryon Oscillation Spectroscopic Survey (BOSS) galaxy survey using SimBIG , a new framework for cosmological inference that leverages high-fidelity simulations and deep generative models. We use two clustering statistics beyond the standard power spectrum: the bispectrum and a summary of the galaxy field based on a convolutional neural network. We constrain H 0 and S 8 1.5 and 1.9 times more tightly than power spectrum analyses. With this increased precision, our constraints are competitive with those of other cosmological probes, even with only 10% of the full BOSS volume. Future work extending SimBIG to upcoming spectroscopic galaxy surveys (DESI, PFS, Euclid) will produce improved cosmological constraints that will develop understanding of cosmic tensions. By extracting non-Gaussian cosmological information on galaxy clustering at nonlinear scales, a framework for cosmic inference (S im BIG) provides more precise constraints for testing cosmological models.

The CMB is a powerful probe of early-universe physics but is only observed after passing through large-scale structure, which changes the observed spectra in important model-dependent ways. This is of particular concern given recent claims of significant discrepancies with low redshift data sets when a standard \\(\\Lambda\\)CDM model is assumed. By using empirical measurements of the CMB lensing reconstruction, combined with weak priors on the smoothness of the lensing spectrum, foregrounds, and shape of any additional integrated Sachs-Wolfe effect, we show how the early-universe parameters can be constrained from CMB observations almost independently of the late-time evolution. This provides a way to test new models for early-universe physics, and measure early-universe parameters, independently of late-time cosmology. Using the empirical measurement of lensing keeps the size of the effect of late-time modelling uncertainty under control, leading to only modest increases in error bars of most early-universe parameters compared to assuming a full evolution model. We provide robust constraints on early-\\(\\Lambda\\)CDM model parameters using the latest Planck PR4 data and show that with future data marginalizing over a single lensing amplitude parameter is sufficient to remove sensitivity to late-time cosmological model only if the spectral shape matches predictions.

The overall cosmological parameter tension between the Atacama Cosmology Telescope 2020 (ACT) and Planck 2018 data within the concordance cosmological model is quantified using the suspiciousness statistic to be 2.6\\(\\sigma\\). Between ACT and the South Pole Telescope (SPT) we find a tension of 2.4\\(\\sigma\\), and 2.8\\(\\sigma\\) between ACT and Planck+SPT combined. While it is unclear whether the tension is caused by statistical fluctuations, systematic effects or new physics, caution should be exercised in combining these cosmic microwave background datasets in the context of the \\(\\Lambda\\)CDM standard model of the universe.