Constraining the halo mass function with observations

The abundances of dark matter halos in the universe are described by the halo mass function (HMF). It enters most cosmological analyses and parametrizes how the linear growth of primordial perturbations is connected to these abundances. Interestingly, this connection can be made approximately cosmology independent. This made it possible to map in detail its near-universal behavior through large-scale simulations. However, such simulations may suffer from systematic effects, especially if baryonic physics is included. In this paper we ask how well observations can constrain directly the HMF. The observables we consider are galaxy cluster number counts, galaxy cluster power spectrum and lensing of type Ia supernovae. Our results show that DES is capable of putting the first meaningful constraints on the HMF, while both Euclid and J-PAS can give stronger constraints, comparable to the ones from state-of-the-art simulations. We also find that an independent measurement of cluster masses is even more important for measuring the HMF than for constraining the cosmological parameters, and can vastly improve the determination of the halo mass function. Measuring the HMF could thus be used to cross-check simulations and their implementation of baryon physics. It could even, if deviations cannot be accounted for, hint at new physics.Comment: v2: small improvements to the text; matches accepted version. 13 pages, 8 figure

Turning noise into signal: learning from the scatter in the Hubble diagram

The supernova (SN) Hubble diagram residual contains valuable information on both the present matter power spectrum and its growth history. In this paper we show that this information can be retrieved with precision by combining both peculiar velocity and weak-lensing analysis on the data. To wit, peculiar velocity induces correlations on the nearby SN while lensing induces a non-Gaussian dispersion in faraway objects. We show that both effects have almost orthogonal degeneracies and discuss how they can be extracted simultaneously from the data. We analyze the JLA supernova catalog in a 14-dimensional parameter space, assuming a flexible growth-rate index $\gamma$. We arrive at the following marginalized constraints: $\sigma_8 = 0.65^{+0.23}_{-0.37}$ and $\gamma = 1.38^{+1.7}_{-0.65}$. Assuming instead GR as the correct gravitation theory (and thus $\gamma \equiv 0.55$), the constraints in $\sigma_8$ tighten further: $\sigma_8 = 0.40^{+0.21}_{-0.23}$. We show that these constraints complement well the ones obtained from other datasets and that they could improve substantially with more SNe.Comment: v2: Real data results corrected; forecast for future data added; discussion extended. v3: Improved discussion; matches published version. 8 figs 15 page

Constraining the growth of perturbations with lensing of supernovae

A recently proposed technique allows one to constrain both the background and perturbation cosmological parameters through the distribution function of supernova Ia apparent magnitudes. Here we extend this technique to alternative cosmological scenarios, in which the growth of structure does not follow the $\Lambda$CDM prescription. We apply the method first to the supernova data provided by the JLA catalog combined with all the current independent redshift distortion data and with low-redshift cluster data from Chandra and show that although the supernovae alone are not very constraining, they help in reducing the confidence regions. Then we apply our method to future data from LSST and from a survey that approximates the Euclid satellite mission. In this case we show that the combined data are nicely complementary and can constrain the normalization $\sigma_8$ and the growth rate index $\gamma$ to within $0.6\%$ and $7\%$, respectively. In particular, the LSST supernova catalog is forecast to give the constraint $\gamma (\sigma_8/0.83)^{6.7} = 0.55 \pm 0.1$. We also report on constraints relative to a step-wise parametrization of the growth rate of structures. These results show that supernova lensing serves as a good cross-check on the measurement of perturbation parameters from more standard techniques.Comment: 9 pages, 7 figures, matches version accepted for publication in MNRAS. Added appendix with fits of lensing moments as function of (z, \sigma_8, \gamma). The updated turboGL 3.0 code can be downloaded at http://www.turbogl.or

Psicología de los juegos olímpicos : la percepción de los entrenadores

Recent studies (Gould, 2001a, b, Greenleaf et al., 2001) have found that specific characteristics are required for Olympic competition. This means that a special psychological attitude must be adopted by athletes. At the same time, a close relationship between coaches and athletes is generally seen as essential in maximizing the athletes performance, and coaches therefore play a very important role in the whole process of the athletes psychological preparation. The general purpose of this research study was to examine coaches perceptions of the specific needs and commitments that are required for the Olympic Games and the way in which athletes must adapt psychologically. Nine Portuguese coaches, who accompanied their athletes to the Sydney Olympic Games, participated in the study. In five cases, their athletes results met/exceeded their expectations, while in the remaining four cases the results were lower than expected. Structured interviews were used to compile data, which was then analysed according to procedures recommended by Miles and Huberman (1984). The conclusions show that the coaches regard the Olympics as having specific characteristics that make the games unique in comparison with other international events. These factors led the athletes to react differently in relation to other major sporting events, with either positive or negative repercussions on their performance. Furthermore, a different reaction to the specific difficulties that the Olympic Games involve was seen to have been made by those athletes that performed the best and those that performed the worst

Incorporation of industrial wastes from thermal processes in cement mortars

This work presents the results of the incorporation of some industrial wastes from thermal processes in cement mortars. Employed wastes were generated in electric arc furnace (EAF) steelmaking and in steel foundry production. Namely, research with mortars containing EAF dusts and foundry sands and slags were conducted. Mechanical and environmental evaluation has been done, to compare the waste containing cement mortars samples with the normal one. The results indicated that the incorporation of these wastes generated in thermal processes in cement mortars does not affect significantly the mechanical properties, namely the flexural and compressive strength, and does not induce any relevant environmental impact when the materials have to be considered as waste, at the end of their life cycle. As a matter of fact, the cement mortar, if becoming a residue, may be considered as an inert one. The results of this work indicate that the incorporation of these wastes in cement mortars is an adequate waste management option.Este trabajo presenta los resultados de la incorporación de algunos residuos industriales generados a partir de procesos térmicos en los morteros de cemento. Los residuos son los generados en hornos de arco eléctrico (EAF) de producción de acero y en la producción de fundición de acero. Se llevó a cabo la investigación con morteros que contienen estos polvos, arenas y escorias de fundición. Se realizó una evaluación mecánica y ambiental para comparar los morteros que contienen residuos con el normal. Los resultados indicaron que la incorporación de estos residuos en los morteros de cemento no afecta significativamente las propiedades mecánicas, es decir, resistencia a la flexión y resistencia a la compresión, y no provocan ningún impacto ambiental pertinente cuando el material tiene que ser considerado como residuo, en el final de su ciclo de vida. Efectivamente, si el mortero de cemento, se convertirse en un residuo, ello se puede considerar como un residuo inerte. Los resultados de este trabajo indican que la incorporación de estos residuos en cementos es una vía de gestión adecuad

Load forecast on a Micro Grid level through Machine Learning algorithms

As Micro Redes constituem um sector em crescimento da indústria energética, representando uma mudança de paradigma, desde as remotas centrais de geração até à produção mais localizada e distribuída. A capacidade de isolamento das principais redes elétricas e atuar de forma independente tornam as Micro Redes em sistemas resilientes, capazes de conduzir operações flexíveis em paralelo com a prestação de serviços que tornam a rede mais competitiva. Como tal, as Micro Redes fornecem energia limpa eficiente de baixo custo, aprimoram a coordenação dos ativos e melhoram a operação e estabilidade da rede regional de eletricidade, através da capacidade de resposta dinâmica aos recursos energéticos. Para isso, necessitam de uma coordenação de gestão inteligente que equilibre todas as tecnologias ao seu dispor. Daqui surge a necessidade de recorrer a modelos de previsão de carga e de produção robustos e de confiança, que interligam a alocação dos recursos da rede perante as necessidades emergentes. Sendo assim, foi desenvolvida a metodologia HALOFMI, que tem como principal objetivo a criação de um modelo de previsão de carga para 24 horas. A metodologia desenvolvida é constituída, numa primeira fase, por uma abordagem híbrida de multinível para a criação e escolha de atributos, que alimenta uma rede neuronal (Multi-Layer Perceptron) sujeita a um ajuste de híper-parâmetros. Posto isto, numa segunda fase são testados dois modos de aplicação e gestão de dados para a Micro Rede. A metodologia desenvolvida é aplicada em dois casos de estudo: o primeiro é composto por perfis de carga agregados correspondentes a dados de clientes em Baixa Tensão Normal e de Unidades de Produção e Autoconsumo (UPAC). Este caso de estudo apresenta-se como um perfil de carga elétrica regular e com contornos muito suaves. O segundo caso de estudo diz respeito a uma ilha turística e representa um perfil irregular de carga, com variações bruscas e difíceis de prever e apresenta um desafio maior em termos de previsão a 24-horas A partir dos resultados obtidos, é avaliado o impacto da integração de uma seleção recursiva inteligente de atributos, seguido por uma viabilização do processo de redução da dimensão de dados para o operador da Micro Rede, e por fim uma comparação de estimadores usados no modelo de previsão, através de medidores de erros na performance do algoritmo.Micro Grids constitute a growing sector of the energetic industry, representing a paradigm shift from the central power generation plans to a more distributed generation. The capacity to work isolated from the main electric grid make the MG resilient system, capable of conducting flexible operations while providing services that make the network more competitive. Additionally, Micro Grids supply clean and efficient low-cost energy, enhance the flexible assets coordination and improve the operation and stability of the of the local electric grid, through the capability of providing a dynamic response to the energetic resources. For that, it is required an intelligent coordination which balances all the available technologies. With this, rises the need to integrate accurate and robust load and production forecasting models into the MG management platform, thus allowing a more precise coordination of the flexible resource according to the emerging demand needs. For these reasons, the HALOFMI methodology was developed, which focus on the creation of a precise 24-hour load forecast model. This methodology includes firstly, a hybrid multi-level approach for the creation and selection of features. Then, these inputs are fed to a Neural Network (Multi-Layer Perceptron) with hyper-parameters tuning. In a second phase, two ways of data operation are compared and assessed, which results in the viability of the network operating with a reduced number of training days without compromising the model's performance. Such process is attained through a sliding window application. Furthermore, the developed methodology is applied in two case studies, both with 15-minute timesteps: the first one is composed by aggregated load profiles of Standard Low Voltage clients, including production and self-consumption units. This case study presents regular and very smooth load profile curves. The second case study concerns a touristic island and represents an irregular load curve with high granularity with abrupt variations. From the attained results, it is evaluated the impact of integrating a recursive intelligent feature selection routine, followed by an assessment on the sliding window application and at last, a comparison on the errors coming from different estimators for the model, through several well-defined performance metrics

Synonymy and Identity of Proofs - A Philosophical Essay

The main objective of the dissertation is to investigate from a strictly philosophical perspective different approaches and results related to the problem of identity of proofs, which is a problem of general proof theory at the intersection of mathematics and philosophy. The author characterizes,compares and evaluates a range of formal criteria of proof-identity that have been proposed in the proof-theoretic literature. While these proposals come from mathematical logicians, the author’s background in both mathematical logic and philosophy allows him to present and discuss these proposals in a manner that is accessible to and fruitful for philosophers, especially those working in logic and philosophy of mathematics, as well as mathematical logicians. The dissertation is structured into a prologue and five sections. In the prologue, the author traces the development of the concept of a proof in ancient philosophy, culminating in the work of Aristotle. In Section I, the author turns to the roots of proof theory in modern philosophy, offering a detailed interpretation of Kant’s “Die falsche Spitzfindigkeit der vier syllogistischen Figuren”, which uncovers interesting links between Kant’s inferences of understanding and of reason and modern proof-theoretic semantics. In Section II, the author turns from historical to systematic considerations concerning different kinds of identity-criteria of proofs, ranging from overly liberal criteria that trivialize proof identity to overly strict, syntactical criteria. In Section III, the heart of the dissertation, the author offers a thorough philosophical discussion of the normalisation thesis. In Section IV, the author considers the difficulties encountered in his discussion of identity of proofs --- particularly of the normalisation thesis --- through the lens of a discussion of the notion of synonymy, and compares this thesis with other possible formal accounts of identity of proofs. In particular, by recourse to Carnap’s notion of synonymy, developed in “Meaning and Necessity”, the author proposes a notion of synonymy of proofs. In Section V, the final substantial section, the author compares the normalisation thesis to the Church-Turing thesis, thereby adducing another dimension of evaluation of the former