Non-Gaussianities and Preheating from N-flation and Magnetogenesis via rotating cosmic string loops

In this thesis we examine multi-field inflationary models of the early Universe. Since non-Gaussianities may allow for the possibility to discriminate between models of inflation, we compute deviations from a Gaussian spectrum of primordial perturbations by extending the delta-N formalism. We use N-flation as a concrete model; our findings show that these models are generically indistinguishable as long as the slow roll approximation is still valid. Besides computing non-Guassinities, we also investigate Preheating after multi-field inflation. Within the framework of N-flation, we find that preheating via parametric resonance is suppressed, an indication that it is the old theory of preheating that is applicable. In addition to studying non-Gaussianities and preheatng in multi-field inflationary models, we study magnetogenesis in the early universe. To this aim, we propose a mechanism to generate primordial magnetic fields via rotating cosmic string loops. Magnetic fields in the micro-Gauss range have been observed in galaxies and clusters, but their origin has remained elusive. We consider a network of strings and find that rotating cosmic string loops, which are continuously produced in such networks, are viable candidates for magnetogenesis with relevant strength and length scales, provided we use a high string tension and an efficient dynamo.

Principles of Pitch Organization in Béla Bartók's 'Duke Bluebeard's Castle'

The topic of my doctoral thesis is to demonstrate the usefulness of incorporating tonal and modal elements into a pitch-web square analysis of Béla Bartók's (1881-1945) opera, 'A kékszakállú herceg vára' ('Duke Bluebeard's Castle'). My specific goal is to demonstrate that different musical materials, which exist as foreground melodies or long-term key progressions, are unified by the unordered pitch set {0,1,4}, which becomes prominent in different sections of Bartók's opera. In Bluebeard's Castle, the set {0,1,4} is also found as a subset of several tetrachords: {0,1,4,7}, {0,1,4,8}, and {0,3,4,7}. My claim is that {0,1,4} serves to link music materials between themes, between sections, and also between scenes. This study develops an analytical method, drawn from various theoretical perspectives, for conceiving superposed diatonic spaces within a hybrid pitch-space comprised of diatonic and chromatic features. The integrity of diatonic melodic lines is retained, which allows for a non-reductive understanding of diatonic superposition, without appealing to pitch centers or specifying complete diatonic collections. Through combining various theoretical insights of the Hungarian scholar Ernő Lendvai, and the American theorists Elliott Antokoletz, Paul Wilson and Allen Forte, as well as the composer himself, this study gives a detailed analysis of the opera's pitch material in a way that combines, complements, and expands upon the studies of those scholars. The analyzed pitch sets are represented on Aarre Joutsenvirta's note-web square, which adds a new aspect to the field of Bartók analysis. Keywords: Bartók, Duke Bluebeard's Castle (Op. 11), Ernő Lendvai, axis system, Elliott Antokoletz, intervallic cycles, intervallic cells, Allen Forte, set theory, interval classes, interval vectors, Aarre Joutsenvirta, pitch-web square, pitch-web analysis.

Oikein, nurin - miten Suomessa kudin : Tutkimus neulonnan työotteista.

The aim of this work was to study what kind of working grips people use to knit in Finland and decide if one grip is superior to others. I investigated how knitters have adopted their grips and how they experience their knitting. I also explored whether it is possible to change one's grip. To provide a theoretical basis for the research I observed knitting in terms of culture, skill and ergonomics. The first part of the study material comprised video recordings of the grips of 95 knitters together with background information collected via a questionnaire during the education of craft teachers at the University of Helsinki in spring 2004, 2005 and 2006. Using the data obtained I focused on three knitters, whose grip of the knitting needles clearly differed from the ergonomically good grip. In addition to them I interviewed one student, who had changed over to more ergonomic way of knitting after participating in the first part of this study. In this respect my study is a several events' case study. In order to analyse my data I used both qualitative and quantitative content analysis methods to complement each other. Most of my research participants had learned to knit in first years of elementary school or comprehensive school. Almost everyone had adopted the basics of knitting by imitating, and many of them had corrected "incorrect" positions from verbal instructions. Through practice the imitated position had gradually become the style unique to each knitter. The findings showed that students' background in knitting is quite varied due to the diverse level of craft teaching. This is reflected in their knitting grips and their interest in knitting. Students do not think that there is one right working grip. The most important thing is that working seems as fluent and relaxed as possible, at which point knitting is easy and flows freely. They often consider their own style so pleasing and well-functioning that they do not think there could be any room for improvement. This study pointed out that, while it is possible to change a knitter's working grip, there is a bigger challenge in acknowledging weaknesses in one's know how. According to the results of my research, the most common working grip among Finnish knitters' corresponds with the grip that has been described as ergonomically good. Over one third of all participants knitted this way. Hands keep the knitting firmly but without tension. The forefinger that guides the yarn from the ball rests gently against the knitting needle, and the yarn goes in front of the first joint of the forefinger. The position of the hands and loops is the same as in the ergonomically good grip, i.e. the fingertips of both hands and the loops are near the tips of the knitting needles, so that the fingers only have to move small distances. When knitters purl and plain, they commonly pick up the yarn from the back of the knitting needle in the same way as when knitting. While researching the common features of working grips I have learned what abnormal grips are like. Although I recognized many different ways to knit, all the peculiar grips were modifications of the continental way of knitting. The results of this study give a clear picture of those points knitters should focus their attention on in order to gain a good hold of the needles.