Noncommutative Quantum Field Theory : Problem of Time and Some Applications

In this thesis the current status and some open problems of noncommutative quantum field theory are reviewed. The introduction aims to put these theories in their proper context as a part of the larger program to model the properties of quantized space-time. Throughout the thesis, special focus is put on the role of noncommutative time and how its nonlocal nature presents us with problems. Applications in scalar field theories as well as in gauge field theories are presented. The infinite nonlocality of space-time introduced by the noncommutative coordinate operators leads to interesting structure and new physics. High energy and low energy scales are mixed, causality and unitarity are threatened and in gauge theory the tools for model building are drastically reduced. As a case study in noncommutative gauge theory, the Dirac quantization condition of magnetic monopoles is examined with the conclusion that, at least in perturbation theory, it cannot be fulfilled in noncommutative space.

Empire, Tourism, Nostalgia: Joseph Brodsky and Travel Writing

Joseph Brodsky, one of the most influential Russian intellectuals of the late Soviet period, was born in Leningrad in 1940, emigrated to the United States in 1972, received the Nobel Prize for Literature in 1987, and died in New York City in 1996. Brodsky was one of the leading public figures of Soviet emigration in the Cold War period, and his role as a model for the constructing of Russian cultural identities in the last years of the Soviet Union was, and still is, extremely important. One of Joseph Brodsky’s great contributions to Russian culture of the latter half of the twentieth century is the wide geographical scope of his poetic and prose works. Brodsky was not a travel writer, but he was a traveling writer who wrote a considerable number of poems and essays which relate to his trips and travels in the Soviet empire and outside it. Travel writing offered for Brodsky a discursive space for negotiating his own transculturation, while it also offered him a discursive space for making powerful statements about displacement, culture, history and geography, time and space—all major themes of his poetry. In this study of Joseph Brodsky’s travel writing I focus on his travel texts in poetry and prose, which relate to his post-1972 trips to Mexico, Brazil, Turkey, and Venice. Questions of empire, tourism, and nostalgia are foregrounded in one way or another in Brodsky’s travel writing performed in emigration. I explore these concepts through the study of tropes, strategies of identity construction, and the politics of representation. The theoretical premises of my work draw on the literary and cultural criticism which has evolved around the study of travel and travel writing in recent years. These approaches have gained much from the scholarly experience provided by postcolonial critique. Shifting the focus away from the concept of exile, the traditional framework for scholarly discussions of Brodsky’s works, I propose to review Brodsky’s travel poetry and prose as a response not only to his exilic condition but to the postmodern and postcolonial landscape, which initially shaped the writing of these texts. Discussing Brodsky’s travel writing in this context offers previously unexplored perspectives for analyzing the geopolitical, philosophical, and linguistic premises of his poetic imagination. By situating Brodsky’s travel writing in the geopolitical landscape of postcolonial postmodernity, I attempt to show how Brodsky’s engagement with his contemporary cultural practices in the West was incorporated into his Russian-language travel poetry and prose and how this engagement thus contributed to these texts’ status as exceptional and unique literary events within late Soviet Russian cultural practices.

Quantum Space-Time and Noncommutative Gauge Field Theories

Arguments arising from quantum mechanics and gravitation theory as well as from string theory, indicate that the description of space-time as a continuous manifold is not adequate at very short distances. An important candidate for the description of space-time at such scales is provided by noncommutative space-time where the coordinates are promoted to noncommuting operators. Thus, the study of quantum field theory in noncommutative space-time provides an interesting interface where ordinary field theoretic tools can be used to study the properties of quantum spacetime. The three original publications in this thesis encompass various aspects in the still developing area of noncommutative quantum field theory, ranging from fundamental concepts to model building. One of the key features of noncommutative space-time is the apparent loss of Lorentz invariance that has been addressed in different ways in the literature. One recently developed approach is to eliminate the Lorentz violating effects by integrating over the parameter of noncommutativity. Fundamental properties of such theories are investigated in this thesis. Another issue addressed is model building, which is difficult in the noncommutative setting due to severe restrictions on the possible gauge symmetries imposed by the noncommutativity of the space-time. Possible ways to relieve these restrictions are investigated and applied and a noncommutative version of the Minimal Supersymmetric Standard Model is presented. While putting the results obtained in the three original publications into their proper context, the introductory part of this thesis aims to provide an overview of the present situation in the field.

An Empirical Study of the Mixture of Time and Movements in Prices

This paper investigates the persistent pattern in the Helsinki Exchanges. The persistent pattern is analyzed using a time and a price approach. It is hypothesized that arrival times are related to movements in prices. Thus, the arrival times are defined as durations and formulated as an Autoregressive Conditional Duration (ACD) model as in Engle and Russell (1998). The prices are defined as price changes and formulated as a GARCH process including duration measures. The research question follows from market microstructure predictions about price intensities defined as time between price changes. The microstructure theory states that long transaction durations might be associated with both no news and bad news. Accordingly, short durations would be related to high volatility and long durations to low volatility. As a result, the spread will tend to be larger under intensive moments. The main findings of this study are 1) arrival times are positively autocorrelated and 2) long durations are associated with low volatility in the market.

On Musical Self-Similarity : Intersemiosis as Synecdoche and Analogy

Self-similarity, a concept taken from mathematics, is gradually becoming a keyword in musicology. Although a polysemic term, self-similarity often refers to the multi-scalar feature repetition in a set of relationships, and it is commonly valued as an indication for musical coherence and consistency . This investigation provides a theory of musical meaning formation in the context of intersemiosis, that is, the translation of meaning from one cognitive domain to another cognitive domain (e.g. from mathematics to music, or to speech or graphic forms). From this perspective, the degree of coherence of a musical system relies on a synecdochic intersemiosis: a system of related signs within other comparable and correlated systems. This research analyzes the modalities of such correlations, exploring their general and particular traits, and their operational bounds. Looking forward in this direction, the notion of analogy is used as a rich concept through its two definitions quoted by the Classical literature: proportion and paradigm, enormously valuable in establishing measurement, likeness and affinity criteria. Using quantitative qualitative methods, evidence is presented to justify a parallel study of different modalities of musical self-similarity. For this purpose, original arguments by Benoît B. Mandelbrot are revised, alongside a systematic critique of the literature on the subject. Furthermore, connecting Charles S. Peirce s synechism with Mandelbrot s fractality is one of the main developments of the present study. This study provides elements for explaining Bolognesi s (1983) conjecture, that states that the most primitive, intuitive and basic musical device is self-reference, extending its functions and operations to self-similar surfaces. In this sense, this research suggests that, with various modalities of self-similarity, synecdochic intersemiosis acts as system of systems in coordination with greater or lesser development of structural consistency, and with a greater or lesser contextual dependence.

ICT and the Shaping of Society: Exploring Human -ICT Relationships in Everyday Life (summary section only)

This thesis explores the relationship between humans and ICTs (information and communication technologies). As ICTs are increasingly penetrating all spheres of social life, their role as mediators – between people, between people and information, and even between people and the natural world – is expanding, and they are increasingly shaping social life. Yet, we still know little of how our life is affected by their growing role. Our understanding of the actors and forces driving the accelerating adoption of new ICTs in all areas of life is also fairly limited. This thesis addresses these problems by interpretively exploring the link between ICTs and the shaping of society at home, in the office, and in the community. The thesis builds on empirical material gathered in three research projects, presented in four separate essays. The first project explores computerized office work through a case study. The second is a regional development project aiming at increasing ICT knowledge and use in 50 small-town families. In the third, the second project is compared to three other longitudinal development projects funded by the European Union. Using theories that consider the human-ICT relationship as intertwined, the thesis provides a multifaceted description of life with ICTs in contemporary information society. By oscillating between empirical and theoretical investigations and balancing between determinist and constructivist conceptualisations of the human-ICT relationship, I construct a dialectical theoretical framework that can be used for studying socio-technical contexts in society. This framework helps us see how societal change stems from the complex social processes that surround routine everyday actions. For example, interacting with and through ICTs may change individuals’ perceptions of time and space, social roles, and the proper ways to communicate – changes which at some point in time result in societal change in terms of, for example, new ways of acting and knowing things.

Time and Location as Customer Perceived Value Drivers

Since the emergence of service marketing, the focus of service research has evolved. Currently the focus of research is shifting towards value co-created by the customer. Consequently, value creation is increasingly less fixed to a specific time or location controlled by the service provider. However, present service management models, although acknowledging customer participation and accessibility, have not considered the role of the empowered customer who may perform the service at various locations and time frames. The present study expands this scope and provides a framework for exploring customer perceived value from a temporal and spatial perspective. The framework is used to understand and analyse customer perceived value and to explore customer value profiles. It is proposed that customer perceived value can be conceptualised as a function of technical, functional, temporal and spatial value dimensions. These dimensions are suggested to have value-increasing and value-decreasing facets. This conceptualisation is empirically explored in an online banking context and it is shown that time and location are more important value dimensions relative to the technical and functional dimensions. The findings demonstrate that time and location are important not only in terms of having the possibility to choose when and where the service is performed. Customers also value an efficient and optimised use of time and a private and customised service location. The study demonstrates that time and location are not external elements that form the service context, but service value dimensions, in addition to the technical and functional dimensions. This thesis contributes to existing service management research through its framework for understanding temporal and spatial dimensions of perceived value. Practical implications of the study are that time and location need to be considered as service design elements in order to differentiate the service from other services and create additional value for customers. Also, because of increased customer control and the importance of time and location, it is increasingly relevant for service providers to provide a facilitating arena for customers to create value, rather than trying to control the value creation process. Kristina Heinonen is associated with CERS, the Center for Relationship Marketing and Service Management at the Swedish School of Economics and Business Administration

Gauge Field Theories, Quantum Space-Time and Some Applications

In this thesis, the possibility of extending the Quantization Condition of Dirac for Magnetic Monopoles to noncommutative space-time is investigated. The three publications that this thesis is based on are all in direct link to this investigation. Noncommutative solitons have been found within certain noncommutative field theories, but it is not known whether they possesses only topological charge or also magnetic charge. This is a consequence of that the noncommutative topological charge need not coincide with the noncommutative magnetic charge, although they are equivalent in the commutative context. The aim of this work is to begin to fill this gap of knowledge. The method of investigation is perturbative and leaves open the question of whether a nonperturbative source for the magnetic monopole can be constructed, although some aspects of such a generalization are indicated. The main result is that while the noncommutative Aharonov-Bohm effect can be formulated in a gauge invariant way, the quantization condition of Dirac is not satisfied in the case of a perturbative source for the point-like magnetic monopole.

Mechanism-based inhibition of CYP2C8 by gemfibrozil in humans : characterisation of time and dose relationships

Drug-drug interactions may cause serious, even fatal clinical consequences. Therefore, it is important to examine the interaction potential of new chemical entities early in drug development. Mechanism-based inhibition is a pharmacokinetic interaction type, which causes irreversible loss of enzyme activity and can therefore lead to unusually profound and long-lasting consequences. The in vitro in vivo extrapolation (IVIVE) of drug-drug interactions caused by mechanism-based inhibition is challenging. Consequently, many of these interactions have remained unrecognised for many years. The concomitant use of the fibrate-class lipid-lowering agent gemfibrozil increases the concentrations of some drugs and their effects markedly. Even fatal cases of rhabdomyolysis occurred in patients administering gemfibrozil and cerivastatin concomitantly. One of the main mechanisms behind this effect is the mechanism-based inhibition of the cytochrome P450 (CYP) 2C8 enzyme by a glucuronide metabolite of gemfibrozil leading to increased cerivastatin concentrations. Although the clinical use of gemfibrozil has clearly decreased during recent years, gemfibrozil is still needed in some special cases. To enable safe use of gemfibrozil concomitantly with other drugs, information concerning the time and dose relationships of CYP2C8 inhibition by gemfibrozil should be known. This work was carried out as four in vivo clinical drug-drug interaction studies to examine the time and dose relationships of the mechanism-based inhibitory effect of gemfibrozil on CYP2C8. The oral antidiabetic drug repaglinide was used as a probe drug for measuring CYP2C8 activity in healthy volunteers. In this work, mechanism-based inhibition of the CYP2C8 enzyme by gemfibrozil was found to occur rapidly in humans. The inhibitory effect developed to its maximum already when repaglinide was given 1-3 h after gemfibrozil intake. In addition, the inhibition was shown to abate slowly. A full recovery of CYP2C8 activity, as measured by repaglinide metabolism, was achieved 96 h after cessation of gemfibrozil treatment. The dose-dependency of the mechanism-based inhibition of CYP2C8 by gemfibrozil was shown for the first time in this work. CYP2C8 activity was halved by a single 30 mg dose of gemfibrozil or by twice daily administration of less than 30 mg of gemfibrozil. Furthermore, CYP2C8 activity was decreased over 90% by a single dose of 900 mg gemfibrozil or twice daily dosing of approximately 100 mg gemfibrozil. In addition, with the application of physiological models to the data obtained in the dose-dependency studies, the major role of mechanism-based inhibition of CYP2C8 in the interaction between gemfibrozil and repaglinide was confirmed. The results of this work enhance the proper use of gemfibrozil and the safety of patients. The information related to time-dependency of CYP2C8 inhibition by gemfibrozil may also give new insights in order to improve the IVIVE of the drug-drug interactions of new chemical entities. The information obtained by this work may be utilised also in the design of clinical drug-drug interaction studies in the future.

Luonnoksia käsityön ruumiillisuudesta. : Käsityö Maurice Merleau-Pontyn ruumiinfenomenologian valossa.

Purpose This study focused on craft from a standpoint of phenomenological philosophy and craft was interpreted through Maurice Merleau-Ponty’s phenomenology of the body. The main focus was the physical phase of the craft process, wherein a product is made from material. The aim was to interpret corporality in craft. There is no former research focusing on lived body in craft science. Physical, bodily making is inalienable in craft, but it is not articulated. Recent discussion has focused on craft as ”whole”, which emphasizes designing part in the process, and craft becomes conceptualized with the theories of art and design. The axiomatic yet silenced basis of craft, corporality, deserves to become examined as well. That is why this study answers the questions: how craft manifests in the light of phenomenology of the body and what is corporality in craft? Methods In this study I cultivated a phenomenological attitude and turned my exploring eye on craft ”in itself”. In addition I restrained myself from mere making and placed myself looking at the occurrence of craft to describe it verbally. I read up Maurice Merleau-Ponty’s phenomenology of the body on his principal work (2002) and former interpretations of it. Interpreting and understanding textual data were based on Gadamer’s hermeneutics, and the four-pronged composition of the study followed Koski’s (1995) version of the Gadamerian process of textual interpretation. Conclusions In the construction of bodily phenomenology craft was to be contemplated as a mutual relationship between the maker and the world materializing in bodily making. At the moment of making a human being becomes one with his craft, and the connection between the maker, material and the equipment appears as communication. Operational dimension was distinctive in the intentionality of craft, which operates in many ways, also in craft products. The synesthesia and synergy of craft were emphasized and craft as bodily practice came to life through them. The moment of making appeared as situation generating time and space, where throwing oneself into making may give the maker an experience of upraise beyond the dualism of mind and body. The conception of the implicit nature of craft knowledge was strengthened. In the light of interpretation it was possible to conceptualize craft as a performance and making ”in itself” as a work of art. In that case craft appeared as bodily expression, which as an experience approaches art without being it after all. The concept of aesthetic was settled into making as well. Bodily and phenomenological viewpoint on craft gave material to critically contemplate the concept of “whole craft” (kokonainen käsityö) and provided different kind of understanding of craft as making.

Effects of environmental variation on ecological and evolutionary dynamics

Environmental variation is a fact of life for all the species on earth: for any population of any particular species, the local environmental conditions are liable to vary in both time and space. In today's world, anthropogenic activity is causing habitat loss and fragmentation for many species, which may profoundly alter the characteristics of environmental variation in remaining habitat. Previous research indicates that, as habitat is lost, the spatial configuration of remaining habitat will increasingly affect the dynamics by which populations are governed. Through the use of mathematical models, this thesis asks how environmental variation interacts with species properties to influence population dynamics, local adaptation, and dispersal evolution. More specifically, we couple continuous-time continuous-space stochastic population dynamic models to landscape models. We manipulate environmental variation via parameters such as mean patch size, patch density, and patch longevity. Among other findings, we show that a mixture of high and low quality habitat is commonly better for a population than uniformly mediocre habitat. This conclusion is justified by purely ecological arguments, yet the positive effects of landscape heterogeneity may be enhanced further by local adaptation, and by the evolution of short-ranged dispersal. The predicted evolutionary responses to environmental variation are complex, however, since they involve numerous conflicting factors. We discuss why the species that have high levels of local adaptation within their ranges may not be the same species that benefit from local adaptation during range expansion. We show how habitat loss can lead to either increased or decreased selection for dispersal depending on the type of habitat and the manner in which it is lost. To study the models, we develop a recent analytical method, Perturbation expansion, to enable the incorporation of environmental variation. Within this context, we use two methods to address evolutionary dynamics: Adaptive dynamics, which assumes mutations occur infrequently so that the ecological and evolutionary timescales can be separated, and via Genotype distributions, which assume mutations are more frequent. The two approaches generally lead to similar predictions yet, exceptionally, we show how the evolutionary response of dispersal behaviour to habitat turnover may qualitatively depend on the mutation rate.

Ecological communities in variable environments : dynamics and diversity under coloured environmental stochasticity

While environmental variation is an ubiquitous phenomenon in the natural world which has for long been appreciated by the scientific community recent changes in global climatic conditions have begun to raise consciousness about the economical, political and sociological ramifications of global climate change. Climate warming has already resulted in documented changes in ecosystem functioning, with direct repercussions on ecosystem services. While predicting the influence of ecosystem changes on vital ecosystem services can be extremely difficult, knowledge of the organisation of ecological interactions within natural communities can help us better understand climate driven changes in ecosystems. The role of environmental variation as an agent mediating population extinctions is likely to become increasingly important in the future. In previous studies population extinction risk in stochastic environmental conditions has been tied to an interaction between population density dependence and the temporal autocorrelation of environmental fluctuations. When populations interact with each other, forming ecological communities, the response of such species assemblages to environmental stochasticity can depend, e.g., on trophic structure in the food web and the similarity in species-specific responses to environmental conditions. The results presented in this thesis indicate that variation in the correlation structure between species-specific environmental responses (environmental correlation) can have important qualitative and quantitative effects on community persistence and biomass stability in autocorrelated (coloured) environments. In addition, reddened environmental stochasticity and ecological drift processes (such as demographic stochasticity and dispersal limitation) have important implications for patterns in species relative abundances and community dynamics over time and space. Our understanding of patterns in biodiversity at local and global scale can be enhanced by considering the relevance of different drift processes for community organisation and dynamics. Although the results laid out in this thesis are based on mathematical simulation models, they can be valuable in planning effective empirical studies as well as in interpreting existing empirical results. Most of the metrics considered here are directly applicable to empirical data.

Nitrous oxide emissions from selected natural and managed northern ecosystems

Microbial activity in soils is the main source of nitrous oxide (N2O) to the atmosphere. Nitrous oxide is a strong greenhouse gas in the troposphere and participates in ozone destructive reactions in the stratosphere. The constant increase in the atmospheric concentration, as well as uncertainties in the known sources and sinks of N2O underline the need to better understand the processes and pathways of N2O in terrestrial ecosystems. This study aimed at quantifying N2O emissions from soils in northern Europe and at investigating the processes and pathways of N2O from agricultural and forest ecosystems. Emissions were measured in forest ecosystems, agricultural soils and a landfill, using the soil gradient, chamber and eddy covariance methods. Processes responsible for N2O production, and the pathways of N2O from the soil to the atmosphere, were studied in the laboratory and in the field. These ecosystems were chosen for their potential importance to the national and global budget of N2O. Laboratory experiments with boreal agricultural soils revealed that N2O production increases drastically with soil moisture content, and that the contribution of the nitrification and denitrification processes to N2O emissions depends on soil type. Laboratory study with beech (Fagus sylvatica) seedlings demonstrated that trees can serve as conduits for N2O from the soil to the atmosphere. If this mechanism is important in forest ecosystems, the current emission estimates from forest soils may underestimate the total N2O emissions from forest ecosystems. Further field and laboratory studies are needed to evaluate the importance of this mechanism in forest ecosystems. The emissions of N2O from northern forest ecosystems and a municipal landfill were highly variable in time and space. The emissions of N2O from boreal upland forest soil were among the smallest reported in the world. Despite the low emission rates, the soil gradient method revealed a clear seasonal variation in N2O production. The organic topsoil was responsible for most of the N2O production and consumption in this forest soil. Emissions from the municipal landfill were one to two orders of magnitude higher than those from agricultural soils, which are the most important source of N2O to the atmosphere. Due to their small areal coverage, landfills only contribute minimally to national N2O emissions in Finland. The eddy covariance technique was demonstrated to be useful for measuring ecosystem-scale emissions of N2O in forest and landfill ecosystems. Overall, more measurements and integration between different measurement techniques are needed to capture the large variability in N2O emissions from natural and managed northern ecosystems.