Modern Cosmology offers us a great understanding of the universe with striking precision, made possible by the modern technologies of the newest generations of telescopes. The standard cosmological model, however, is not absent of theoretical problems and open questions. One possibility that has been put forward is the existence of a coupling between dark sectors. The idea of an interaction between the dark components could help physicists understand why we live in an epoch of the universe where dark matter and dark energy are comparable in terms of energy density, which can be regarded as a strange coincidence given that their time evolutions are completely different. Dark matter and dark energy are generally treated as perfect fluids. Interaction is introduced when we allow for a non-zero term in the right-hand side of their individual energy-momentum tensor conservation equations. We proceed with a phenomenological approach to test models of interaction with observations of redshift-space distortions. In a flat universe composed only of these two fluids, we consider separately two forms of interaction, through terms proportional to the densities of both dark energy and dark matter. An analytic expression for the growth rate approximated as f = Omega^gamma, where Omega is the percentage contribution from the dark matter to the energy content of the universe and gamma is the growth index, is derived in terms of the interaction strength and of other parameters of the model in the first case, while for the second model we show that a non-zero interaction cannot be accommodated by the index growth approximation. The successful expressions obtained are then used to compare the predictions with growth of structure observational data in a Markov Chain Monte Carlo code and we find that the current growth data alone cannot impose constraints on the interaction strength due to their large uncertainties. We also employ observations of galaxy clusters to assess their virial state via the modified Layzer-Irvine equation in order to detect signs of an interaction. We obtain measurements of observed virial ratios, interaction strength, rest virial ratio and departure from equilibrium for a set of clusters. A compounded analysis indicates an interaction strength of 0.29^{+2.25}_{-0.40}, compatible with no interaction, but a compounded rest virial ratio of 0.82^{+0.13}_{-0.14}, which means a 2 sigma confidence level detection. Despite this tension, the method produces encouraging results while still leaves room for improvement, possibly by removing the assumption of small departure from equilibrium. / A cosmologia moderna oferece um ótimo entendimento do universo com uma precisão impressionante, possibilitada pelas tecnologias modernas das gerações mais novas de telescópios. O modelo cosmológico padrão, porém, não é livre de problemas do ponto de vista teórico, deixando perguntas ainda sem respostas. Uma possibilidade que tem sido proposta é a existência de um acoplamento entre setores escuros. A ideia de uma interação entre os componentes escuros poderia ajudar os físicos a entender por que vivemos em uma época do universo na qual a matéria escura e a energia escura são comparáveis em termos de densidades de energia, o que pode ser considerado uma estranha coincidência dado que suas evoluções com o tempo são completamente diferentes. Matéria escura e energia escura são geralmente tratadas como fluidos perfeitos. A interação é introduzida ao permitirmos um tensor não nulo no lado direito das equações de conservação dos tensores de energia-momento. Prosseguimos com uma abordagem fenomenológica para testar modelos de interação com observações de distorções no espaço de redshift. Em um universo plano composto apenas por esses dois fluidos, consideramos, separadamente, duas formas de interação, através de termos proporcionais às densidades de energia escura e de matéria escura. Uma expressão analítica para a taxa de crescimento aproximada por f = Omega^gamma, onde Omega é a contribuição percentual da matéria escura para o conteúdo do universo e gamma é o índice de crescimento, é deduzida em termos da interação e de outros parâmetros do modelo no primeiro caso, enquanto para o segundo caso mostramos que uma interação não nula não pode ser acomodada pela aproximação do índice de crescimento. As expressões obtidas são então utilizadas para comparar as previsões com dados observacionais de crescimento de estruturas em um programa para Monte Carlo via cadeias de Markov. Concluímos que tais dados atuais por si só não são capazes de restringir a interação devido às suas grandes incertezas. Utilizamos também observações de aglomerados de galáxias para analisar seus estados viriais através da equação de Layzer-Irvine modificada a fim de detectar sinais de interação. Obtemos medições de taxas viriais observadas, constante de interação, taxa virial de equilíbrio e desvio do equilíbrio para um conjunto de aglomerados. Uma análise combinada indica uma constante de interação 0.29^{+2.25}_{-0.40}, compatível com zero, mas uma taxa virial de equilíbrio combinada de 0.82^{+0.13}_{-0.14}, o que significa uma detecção em um intervalo de confiança de 2 sigma. Apesar desta tensão, o método produz resultados encorajadores enquanto ainda permite melhorias, possivelmente pela remoção da suposição de pequenos desvios do equilíbrio.

O presente estudo se propõe analisar os traços de personalidade do Dark Triad na decisão de manipular resultados para maximização de ganhos pessoais e empresariais. Para a discussão teórica considerou-se o Dark Triad, composto por traços não patológicos do Narcisismo, da Psicopatia e do Maquiavelismo e também a investigação do uso oportunístico da informação contábil-financeira quanto à decisão de manipular resultados, fundamentada pela Teoria dos Altos Escalões. Adotou-se a abordagem metodológica teórico-empírica. Os dados foram coletados usando um questionário survey divido em quatro partes: perfil demográfico, instrumento de medição de personalidade - Short Dark Triad (SD3), uma Simulação Empresarial com assertivas decisórias com enfoque em manobras financeiras e um jogo no formato Loteria. Três estudos foram realizados para adaptar o SD3 para uso no Brasil e testar três hipóteses formuladas. O Estudo 1 utilizou uma amostra de 30 alunos de Ciências Contábeis; o Estudo 2 utilizou uma amostra de 131 estudantes de MBA na área de Gestão Financeira. Ambos os estudos foram conduzidos como um teste preliminar para ajustar o questionário para o Estudo 3. Os dados para o estudo 3 foram coletadas de 263 gestores, os quais possuíam mais de seis meses de experiência. Técnicas de estatística descritiva, correlação análise, teste de hipóteses e regressão logística permitiram evidenciar, no Estudo 3, uma correlação significativa entre os três traços de personalidade. O Maquiavelismo e a Psicopatia apresentaram o maior valor correlacional. Existe uma relação positiva entre os altos traços de Maquiavelismo e Psicopatia e a decisão de manipular resultados. Em relação aos níveis, os traços moderados e altos do Maquiavelismo apresentaram maior aproximação. Já os traços da Psicopatia baixo e moderado demonstraram maior aproximação, permitindo a inferência de que o traço moderado apresenta menor tendência de os gestores decidirem pela manipulação de resultados. O Narcisismo não revelou diferenças entre médias, não sendo possível analisar os seus níveis. O estudo confirmou a relação positiva entre a interação dos três tipos de personalidade que compõem o Dark Triad e a decisão de manipular resultados. Os resultados levam à defesa da tese proposta de que a disposição de manipular resultados para a maximização de ganhos pessoais e empresariais está associada à interação de Maquiavelismo, Narcisismo e Psicopatia e aos níveis (baixo, moderado e alto) de pelo menos um desses traços que compõem o Dark Triad. Assim, este estudo contribui teórica, prática e metodologicamente para a área contábil, sobretudo para o campo da contabilidade comportamental, por discutir uma temática psicológica inovadora no contexto nacional; oferecer às empresas insights para o reconhecimento dos aspectos positivos e negativos em gestores dotados desses traços, no sentido de acompanhar mais de perto suas ações, para se tentar evitar prejuízos organizacionais; desperta para a análise de fatores comportamentais como potenciais influenciadores da tomada de decisão de manipular resultados; além de apresenta à sociedade brasileira a possibilidade de conhecimento, reconhecimento e convivência com indivíduos que exteriorizam esses traços de personalidade. / This study seeks to analyze the Dark Triad personality traits in the decision to manipulate earnings in order to maximize personal and business earnings. For the theoretical discussion, it was considered the Dark Triad of personality, composed by non-pathological traits of Narcissism, psychopathy and Machiavellianism and also, the opportunistic use of the financial-accounting information, regarding the decision to manipulate earnings, grounded on the Upper Echelon Theory. A theoretical and empirical methodology was employed. Data were collected using survey questionnaire divided into four parts: demographic profile, personality measurement tool - Short Dark Triad (SD3), a Business Simulation with assertive decision-making with a focus on financial maneuvers and a game in the Lottery format. In order to adapt the SD3 for use in Brazil and to test three formulated hypotheses, three studies were carried out. The Study 1 used a sample of 30 accountancy students; Study 2 used a sample of 131 MBA students in the area of Financial Management. Both studies were conducted as a preliminary test to adjust the questionnaire to Study 3. Data for Study 3 were collected from 263 managers, which have had more than six months of experience. Descriptive statistics, correlation analysis, hypotheses tests and logistical regression evidenced a significant correlation among the three personality traits. The highest correlation was found between Machiavellianism and psychopathy. There was a significant positive relationship between high incidence of Machiavellianism and psychopathy traits and the decision to manipulate earnings. Regarding the levels, the high and moderate traits of Machiavellianism showed greater approximation. On the other hand, moderate and low traits of Psychopathy showed greater approximation, allowing for the inference that the moderate trait indicates a smaller tendency of managers deciding to manipulate the earnings. Narcissism did not reveal differences between the averages, which made it impossible to analyze its levels. The study confirmed the positive relationship between the interaction of the three Dark Triad personality traits and the decision to manipulate earnings. Therefore, the results confirm the proposed thesis that the decision to manipulate earnings to maximize personal and business earnings is associated with the interaction of Machiavellianism, Narcissism and psychopathy and the levels (low, moderate and high) of, at least, one of these Dark Triad traits. This study contributes theoretically, practically and methodologically to the field of Behavioral accounting. It discussed an innovative psychological theme in the national environment. The knowledge of the attributes of these personality traits may offer businesses insights to recognize the benefits and drawbacks of living with these types of managers and following more closely their actions, especially, to avoid organizational damage. Recognizing these traits in the others and in one\'s self may promote a more pleasant coexistence, by learning to deal with exteriorized behavior without the purpose of making these individual characteristics public out of respect for the involved ethical questions.

An abundance of cosmological evidence suggests that cold dark matter exists and makes up 83% of the matter in the universe. At the same time, this dark matter has eluded direct detection and its identity remains a mystery. Many large international collaborations are actively searching for dark matter through its potential annihilation in high-density regions of the universe, its creation in particle accelerators, and its interaction with Standard Model particles in low-background detectors. One of the most promising dark matter candidates is the weakly interacting massive particle (WIMP) which falls naturally out of extensions of the Standard Model. A variety of detectors have been employed in the search for WIMPs, which are expected to scatter with atomic nuclei, yet none have been more successful than dual-phase liquid xenon time projection chambers (TPCs). The first ton-scale liquid xenon TPC, XENON1T, began operating in 2016 and with only 34.2 days of data has set the most strict limits on the WIMP-nucleon interaction cross sections for WIMP masses above 10 GeV/c^2, with a minimum of 7.7 × 10−47 cm^2 for 35 GeV/c^2 WIMPs. One of the major keys to success for liquid xenon TPCs is our understanding of interactions in the medium through myriad measurements. Given that the expected WIMP scattering rate increases with decreasing interaction energy, there has been more focus in recent years in pushing our understanding of interactions in liquid xenon to lower energies. Additionally, as liquid xenon TPCs operate with a large electric field in the medium, an effort has been made to understand how the signal response of xenon changes as a function of the applied electric field. In this thesis, I describe the details of XENON1T, its calibration and characterization, with a special emphasis on the electronic and nuclear recoil calibrations, and the inaugural WIMP search of XENON1T. I then discuss a dedicated measurement, made in the calibration-optimized liquid xenon TPC neriX, of the signal response of low energy nuclear recoils in liquid xenon at electric fields relevant to the dark matter search. The measurements of signal response in XENON1T and neriX were performed using an analysis framework that I developed to allow a more sophisticated examination of recoil responses using GPU-accelerated simulations.

Nesta dissertação nós propomos uma nova cosmologia relativística acelerada cujo conteúdo material é composto apenas por bárions e matéria escura fria. A não existência de uma componente de energia escura implica que nosso cenário é baseado numa redução do chamado setor escuro do universo. Neste modelo, o presente estágio acelerado é determinado pela pressão negativa descrevendo a produção de partículas de matéria escura fria induzida pelo campo gravitacional variável do universo. Para um universo espacialmente plano ($\\Omega _ + \\Omega _b = 1$), como previsto pela inflação, este tipo de cenário possui somente um parâmetro livre e a equação diferencial governando a evolução do fator de escala é exatamente a mesma do modelo $\\Lambda$CDM. Neste caso, encontramos que o parâmetro efetivo de densidade de matéria é $\\Omega_= 1 - \\alpha$, onde $\\alpha$ é um par\\^metro constante ligado à taxa de criação de matéria escura fria. Aplicando um teste estatístico $\\chi^2$ para os dados de Supernovas do tipo Ia (Union Sample 2008), limitamos os par\\^metros livres do modelo nos casos espacialmente plano e com curvatura. Em particular, encontramos que para o caso plano $\\alpha \\sim 0.71$, de forma que $\\Omega_ \\sim 0.29$, como tem sido inferido independentemente por lentes gravitacionais fracas, estrutura de grande escala, radiação cósmica de fundo e outras observações complementares. / In this dissertation we propose a new accelerating relativistic cosmology whose matter content is composed only by baryons and cold dark matter. The nonexistence of a dark energy component implies that our scenario is based on a reduction of the so-called dark sector of the Universe. The present accelerating stage in this model is powered by the negative pressure des\\-cribing the cold dark matter particle production induced by the variable gravitational field of the Universe. For a spatially flat universe ($\\Omega _ + \\Omega _b = 1$), as predicted by inflation, this kind of scenario has only one free parameter and the differential equation governing the evolution of the scale factor is exactly the same of the $\\Lambda$CDM model. In this case, we find that the effectively observed matter density parameter is $\\Omega_ = 1 - \\alpha$, where $\\alpha$ is a constant parameter related to the cold dark matter creation rate. By applying a $\\chi^2$ statistical test for Supernovae type Ia data (Union Sample 2008), we constrain the free parameters of the model for spatially flat and curved cases. In particular, to the flat case we find $\\alpha \\sim 0.71$, so that $\\Omega_ \\sim 0.29$, as independently inferred from weak gravitational lensing, large scale structure, cosmic background radiation, and other complementary observations.

Uma série de observações advindas da medida da distância de supernovas tipo IA, idade das estrelas mais antigas, anisotropias da radiação cósmica de fundo, entre outras, evidenciam que o universo está passando por uma fase de expansão acelerada. Essa expansão está sendo causada por uma componente misteriosa denominada energia escura, que representa cerca de $70\\%$ do conteúdo total do universo, e cuja natureza é desconhecida. Para descrever a energia escura vários modelos têm sido propostos, entre eles, podemos destacar a energia do vácuo (constante cosmológica) e um campo escalar dinâmico (quintessência). Também são considerados modelos em que a energia escura interage com outro componente misterioso, a matéria escura. Existem vários testes observacionais para vincular os parâmetros desses modelos. Nesta dissertação, exploraremos um método baseado na idade de galáxias em altos redshifts e na idade do universo, conhecido em inglês como lookback time. / A number of observations arising from the measurement of distance of type IA Supernovae, age of oldest stars, anisotropy of cosmic microwave background, among others, show that the universe is undergoing a phase of accelerated expansion. This expansion is being caused by a mysterious component called dark energy, which represents about $70\\%$ of the total content of the universe, and whose nature is unknown. To describe the various dark energy models have been proposed, among them we highlight the vacuum energy (cosmological constant), and a dynamic scalar field (quintessence). Are also considered models in which dark energy interacts with another mysterious component, the dark matter. There are several observational tests to constraint the parameters of these models. In this dissertation, we explore a method based on age of galaxies at high redshift and the age of the universe, known as lookback time.

Flat cosmology with collisionless cold dark matter (CDM) and cosmological constant ([Lambda]CDM cosmology) may have some problems on small scales, even though it has been very successful on large scales. We study the effect of Self-Interacting Dark Matter (SIDM) hypothesis on the density profiles of halos. Collisionless CDM predicts cuspy density profiles toward the center, while observations of low mass galaxies prefer cored profiles. SIDM was proposed by Spergel & Steinhardt [161] as a possible solution to this cuspy profile problem on low-mass scales. On the other hand, observations and collisionless CDM agree on mass scales of galaxy clusters. It is also known that the SIDM hypothesis would contradict with X-ray and gravitational lensing observations of cluster of galaxies, if the cross section were too large. Our final goal is to find the range of SIDM scattering cross section models that are consistent with those astrophysical observations in two different mass scales. There are two theoretical approaches to compute the effect of self-interacting scattering -- Gravitational N-body simulation with Monte Carlo scattering and conducting fluid model; those two approaches, however, had not been confirmed to agree with each other. We first show that two methods are in reasonable agreement with each other for both isolated halos and for halos with realistic mass assembly history in an expanding [Lambda]CDM universe; the value of cross section necessary to have a maximally relaxed low-density core in [Lambda]CDM is in mutual agreement. We then develop a semianalytic model that predicts the time evolution of SIDM halo. Our semianalytic relaxation model enables us to understand how a SIDM halo would relax to a cored profile, and obtain an ensemble of SIDM halos from collisionless simulations with reasonable computational resources. We apply the semianalytic relaxation model to CDM halos, and compare the resulting statistical distribution of SIDM halos with astrophysical observations. We show that there exists a range of scattering cross sections that simultaneously solve the cuspy core problem on low-mass scales and satisfy the galaxy cluster observations. We also present that other potential conflicts between [Lambda]CDM and observations could be resolved in Part II and III. / text

Denna studie har som syfte till att undersöka två dagstidningars och tre resetidningars framställning av Dark Tourism samt ta reda på vilka skillnader och likheter framställningarna har. Målet är även att finna en djupgående uppfattning av Dark Tourism och de olika perspektiven och gemensamma dragen som finns i artiklarna. Det empiriska materialet består av 25 artiklar varav 15 stycken kommer från dagstidningar och 10 stycken kommer ifrån resetidningar. En kritisk diskursanalys har tillämpats som metod i denna studie och resultaten visar att två olika diskurser, varav den ena är melankolisk och den andra är sangvinisk, präglar tidningsgenrerna. Det framgår även att diskurserna som råder i tidningarna kan ha en stor påverkan på människors uppfattning av fenomenet Dark Tourism. / This study aims to examine two daily newspapers and three travel magazines’ production of Dark Tourism, and find out what differences and similarities the petitions have. The aim is also to find an in-depth understanding of Dark Tourism and the different perspectives and common features found in the articles. The empirical material consists of 25 articles, of which 15 were from daily newspapers and 10 come from travel magazines. A critical discourse analysis has been applied as a method in this study and the results show that two different discourses, one of which is melancholic and the other is sanguine, characterizes these journal genres. It is also clear that the discourses that prevail in the newspapers can have a big impact on people's perception of the phenomenon of Dark Tourism.   Keywords: Dark Tourism, Discourse, Newspaper Articles, Critical Discourse Analysis, Media

<p>We examine the Einstein equation coupled to the Klein-Gordon equation for a complex-valued scalar field. These two equations together are known as the Einstein-Klein-Gordon system. In the low-field, non-relativistic limit, the Einstein-Klein-Gordon system reduces to the Poisson-Schrödinger system. We describe the simplest solutions of these systems in spherical symmetry, the spherically symmetric static states, and some scaling properties they obey. We also describe some approximate analytic solutions for these states.</p><p>The EKG system underlies a theory of wave dark matter, also known as scalar field dark matter (SFDM), boson star dark matter, and Bose-Einstein condensate (BEC) dark matter. We discuss a possible connection between the theory of wave dark matter and the baryonic Tully-Fisher relation, which is a scaling relation observed to hold for disk galaxies in the universe across many decades in mass. We show how fixing boundary conditions at the edge of the spherically symmetric static states implies Tully-Fisher-like relations for the states. We also catalog other ``scaling conditions'' one can impose on the static states and show that they do not lead to Tully-Fisher-like relations--barring one exception which is already known and which has nothing to do with the specifics of wave dark matter.</p> / Dissertation

We consider the sensitivity of high luminosity neutrino experiments to light stable states, as arise in scenarios of MeV-scale dark matter. To ensure the correct thermal relic abundance, such states must annihilate to the Standard model via light mediators, providing a portal for access to the dark matter state in colliders or fixed targets. This framework implies that neutrino beams produced at a fixed target will also carry an additional “dark matter beam”, which can mimic neutrino scattering off electrons or nuclei in the detector. We therefore develop a Monte Carlo code to simulate the production of a dark matter beam at two proton fixed-target facilities with high luminosity, LSND and MiniBooNE, and with this simulation determine the existing limits on light dark matter. We find in particular that MeV-scale dark matter scenarios motivated by an explanation of the galactic 511 keV line are strongly constrained. / Graduate

Syftet med studien var att undersöka sambanden mellan Dark Triad (de mörka personlighetsdragen Machiavellism, narcissism och psykopati), Sociosexuell orientering (beteende, attityd och lust till att medverka i tillfälliga sexuella relationer) samt Religiositet. En korrelationsanalys utfördes för att undersöka sambanden mellan variablerna och en modererande multipel regressionsanalys (MMR) utfördes för att undersöka om religiositet modererade effekten av Dark Triad på sociosexuell orientering. Deltagarna bestod av amerikaner (N =309) som svarade på en webbenkät via Amazon Mechanical Turk (MTurk) vilken innehöll Dark Triad Dirty Dozen (DTDD) och the Revised Sociosexual Orientation Inventory (SOI-R), dessutom angav de religionstillhörighet/ingen religionstillhörighet. Dark Triad hade ett positivt samband med sociosexuell orientering, men inget samband med religiositet. Sociosexuell orientering hade ett negativt samband med religiositet. Religiositet modererade inte effekten av Dark Triad på sociosexuell orientering. Resultaten bekräftar delvis tidigare forskning. Trots att religiositet inte modererade effekten av Dark Triad på sociosexuell orientering, borde detta förhållande undersökas vidare eftersom ingen tidigare forskning gjorts på området. / The purpose of this study was to examine the relationships between the Dark Triad (the dark personality traits Machiavellianism, narcissism and psychopathy), Sociosexual orientation (behavior, attitude and desire to participate in uncommited sex) and Religiosity. A correlation analysis was used to investigate the association between variables and a moderating multiple regressionanalysis (MMR) was used to investigate if Religiosity moderated the effect of the Dark Triad on Sociosexual orientation. The participants consisted of US-residents (N = 309) who responded to an online survey through Amazon Mechanical Turk (MTurk) comprising The Dark Triad Dirty Dozen (DTDD) and the Revised Sociosexual Orientation Inventory (SOI-R). In addition participants also stated religious affiliation / no religious affiliation. Dark Triad had a positive relationship with sociosexual orientation, but no relationship with religiosity. Sociosexual orientation had a negative relationship with religiosity. Religiosity did not moderate the effect of Dark Triad on sociosexual orientation. The results partially confirm previous research. Although religiosity failed to moderate the effect of Dark Triad on sociosexual orientation, this relation should be investigated further since no previous research has been done in this field of research.