91 resultados para R(infinity) property


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Einstein's general relativity is a classical theory of gravitation: it is a postulate on the coupling between the four-dimensional, continuos spacetime and the matter fields in the universe, and it yields their dynamical evolution. It is believed that general relativity must be replaced by a quantum theory of gravity at least at extremely high energies of the early universe and at regions of strong curvature of spacetime, cf. black holes. Various attempts to quantize gravity, including conceptually new models such as string theory, have suggested that modification to general relativity might show up even at lower energy scales. On the other hand, also the late time acceleration of the expansion of the universe, known as the dark energy problem, might originate from new gravitational physics. Thus, although there has been no direct experimental evidence contradicting general relativity so far - on the contrary, it has passed a variety of observational tests - it is a question worth asking, why should the effective theory of gravity be of the exact form of general relativity? If general relativity is modified, how do the predictions of the theory change? Furthermore, how far can we go with the changes before we are face with contradictions with the experiments? Along with the changes, could there be new phenomena, which we could measure to find hints of the form of the quantum theory of gravity? This thesis is on a class of modified gravity theories called f(R) models, and in particular on the effects of changing the theory of gravity on stellar solutions. It is discussed how experimental constraints from the measurements in the Solar System restrict the form of f(R) theories. Moreover, it is shown that models, which do not differ from general relativity at the weak field scale of the Solar System, can produce very different predictions for dense stars like neutron stars. Due to the nature of f(R) models, the role of independent connection of the spacetime is emphasized throughout the thesis.

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Evaluation of entrepreneurship in the speech of academic students and newly qualified young academics a summary of a qualitative attitude study. In Finland very few university students plan to become entrepreneurs. The aim of this research was to examine entrepreneurial attitudes expressed in speech. The material was gathered from interviews with university students and newly qualified young academic adults. The interviewees commented on twelve different sentences with claims formulated using research literature and views that have appeared in public discussions. The interviewees were divided into three different groups based on their self-expressed entrepreneurial intentions. The method of qualitative attitude research (Vesala & Rantanen 1999, 2007) was used in the interviews. The research material was studied using two interpretative theories: (1) The planned behaviour theory (Ajzen 1985, 1991a, b), which makes it possible to focus on the separate elements (attitude towards an act, subjective norms and perceived feasibility) necessary for intentions to develop; and (2) The theory of the two images of entrepreneurship (Vesala 1996), where individualism and relationism can be seen as resources for evaluating entrepreneurship. The subject of the research was how university students and newly qualified young adults viewed entrepreneurship as a general phenomen and in relation to the academic world. A second focus was on the attitudes expressed toward entrepreneurial university education and the possibility of combining entrepreneurship and academic knowledge. Of interest were also questions such as whether academic studies, knowledge and the university itself are resources or barriers to entrepreneurial intentions and entrepreneurship whether university students received any support for their entrepreneurial ambitions from the university and their fellow academic students. The problems tackled by this research were thus the following: How was entrepreneurship seen, both as a general phenomen and in an academic context, when it was evaluated positively, negatively or neutrally by the interviewees? In what way was entrepreneurship constructed in the interviewees attitudes? How were entrepreneurship and the academic world related in the interviewees attitudes? What kind of role did the university as an academic context play in the interviewees attitudes for example were university education and academic knowledge seen as resources or barriers to their entrepreneurial intentions. Traditional attitude studies claim that attitudes are a stable property of an individual. In contrast, rhetorical social psychological and qualitative attitude studies emphasize the contextual and linguistic aspects of attitude, and they offered an alternative viewpoint for this research. The study was based on two general assumptions: attitudes have objects and are evaluative. Here attitude was defined as an evaluative interpresentation made towards an object; adopting an attitude is a contextual process in the sense that attitudes are always concerned with the action context of the persons presenting them. Entrepreneurship, both as a general phenomen and in an academic context, was specified as the object to which an attitude was taken. From a theoretical point of view, qualitative methods suited the general structure of this research well. In a particular, qualitative approach which emphasized contextual elements proved to be both empirically valid and useful for avoiding the problematic assumptions associated with traditional attitude study. The subject of the analysis was the argumentative speech produced by the interviewees. The results of the study show the subjects responses to three main ways of viewing entrepreneurships. The first was an individualistic, ideal image of entrepreneurship. This was mostly evaluated positively and gained wide approval especially among interviewees who included entrepreneurship among their employment choices. Entrepreneurship was seen as the decision to earn one s living independently. In this individualistic image of entrepreneurship, the social context was hardly ever mentioned. Elements which were seen to threaten this ideal image were evaluated negatively. When entrepreneurship was evaluated negatively using the individualistic image of entrepreneurship, it was mentioned that it forced one into a never ending cycle of work and uninterested duties. The relationistic image of entrepreneurship was used as a speech resource when the social context was constructed as an economic resource or a threat to the ideal image of entrepreneurship. In the second view, entrepreneurship was characteristically seen as being based on economics, which was seen as a threat to the ideal individualistic image of entrepreneurship. The risk of economic failure was seen as a limiting factor to entrepreneurial ambitions as it forced entrepreneurs to work around the clock. The third view concerned the relationship between entrepreneurship and the academic world. Entrepreneurship as an employment choice for university educated persons was evaluated as relevant, and thus positively, when university education was constructed as a resource for entrepreneurship - and irrelevant and thus negatively when it was construed as an obstacle, too wide, or when successful entrepreneurship was seen as being mostly based on an individual s personal characteristics. The interviewees with no entrepreneurial intentions expressed the view that academic education didn t provide the proper skills and knowledge for entrepreneurship. The interviewees also expressed interest in university entrepreneurship education, although none had experience on this. The interviewees emphasized the fact that the University didn t encourage them to consider entrepreneurship as a relevant employment choice. The assumption made by this study was that becoming an entrepreneur is a conscious decision, the environment may influence an individual s decisions on how to make a living as it tends to socialise people to act in accordance with cultural traditions. Keywords: Entrepreneurship, Attitudes towards entrepreneurship, Intentional behaviour, Entrepreneurial intention, University entrepreneurship education, Qualitative attitude research (Vesala & Rantanen 1999, 2007), Rhetorical social psychology (Billig 1986), The theory of entrepreneuship s two images: individualism and relationism (Vesala 1996 ), The planned behaviour theory (Ajzen 1985, 1991a, b)

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The thesis examines homeowners associations as a part of the large-scale housing reform, implemented in Russia since 2005. The reform transferred housing management from the public sector to the private sector and to the citizens responsibility. The reform is a continuation to the privatisation of the housing stock that was started in Russia in the beginning of the 1990s, aiming to build a market-oriented housing sector in the country. The reform makes a fundamental change to the Soviet system, in which ownership along with management and maintenance of housing were monopolised by the state. Homeowners are now responsible for the management of the common areas in privatised houses, which is often realised by establishing a homeowners association. Homeowners associations are examined by using the so-called common-pool resource regime approach, with the main question being the ways in which taking care of common property collectively succeeds in practice. The study is based on interview data of St. Petersburg s homeowners associations. Using the common-pool resource theory the study demonstrates why implementation of the housing reform has not succeeded as expected. Certain elements that characterise a successful common-pool resource regime do not fulfill sufficiently in St. Petersburg s homeowners associations. Firstly, free-riding, that is, withdrawal from the association s joint decision-making and not making the housing payments is common, as effective sanctions to prevent it are missing in the legislation. That is, eviction or expelling a non-paying member from the association is not possible. Secondly, ownership of the land plot and common areas of the house, such as basements and attics, are often disputed between the associations and authorities. In the Soviet era, these common areas were public property along with the apartments, but in privatised houses they should, according to the legislation, belong to the associations property. Thirdly, solution of disputes between the associations and authorities and within the associations is difficult, as the court system tends to be bureaucratic and inefficient. In addition to the common-pool resource approach, the study also examines how social capital contributes to the associations effectiveness and democratic governance. The study finds that although homeowners associations have increased cooperation and tightened social relations between neighbours, social capital has not been able to prevent free-riding. The study shows that unlike it is often claimed, the so-called Soviet mentality , that is, residents passiveness and unwillingness to participate, is not the most important obstacle to the reform. Instead, the reform is impeded most of all by imperfect institutional arrangements and local authorities that prevent the associations from working as independent, self-governing associations.

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Nowadays any analysis of Russian economy is incomplete without taking into account the phenomenon of oligarchy. Russian oligarchs appeared after the fall of the Soviet Union and are represented by wealthy businessmen who control a huge part of natural resources enterprises and have a big political influence. Oligarchs’ shares in some natural resources industries reach even 70-80%. Their role in Russian economy is big without any doubts, however there has been very little economic analysis done. The aim of this work is to examine Russian oligarchy on micro and macro levels, its role in Russia’s transition and the possible positive and negative outcomes from this phenomenon. For this purpose the work presents two theoretical models. The first part of this thesis work examines the role of oligarchs on micro level, concentrating on the question whether the oligarchs can be more productive owners than other types of owners. To answer the question this part presents a model based on the article “Are oligarchs productive? Theory and evidence” by Y. Gorodnichenko and Y. Grygorenko. It is followed by empirical test based on the works of S. Guriev and A. Rachinsky. The model predicts oligarchs to invest more in the productivity of their enterprises and have higher returns on capital, therefore be more productive owners. According to the empirical test, oligarchs were found to outperform other types of owners, however it is not defined whether the productivity gains offset losses in tax revenue. The second part of the work concentrates on the role of oligarchy on macro level. More precisely, it examines the assumption that the depression after 1998 crises in Russia was caused by the oligarchs’ behavior. This part presents a theoretical model based on the article “A macroeconomic model of Russian transition: The role of oligarchic property rights” by S. Braguinsky and R. Myerson, where the special type of property rights is introduced. After the 1998 crises oligarchs started to invest all their resources abroad to protect themselves from political risks, which resulted in the long depression phase. The macroeconomic model shows, that better protection of property rights (smaller political risk) or/and higher outside investing could reduce the depression. Taking into account this result, the government policy can change the oligarchs’ behavior to be more beneficial for the Russian economy and make the transition faster.

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A theoretical framework of the link between climate change, rural development, sustainable agriculture, poverty, and food security is presented. Some options to respond to climate change are described. Current knowledge and potential effects on agricultural productivity is discussed. Necessary conditions for successful adaptation includes secured property rights to land, institutions that make market access possible and credit possibilities. The options of mitigation and enhanced adaptive capacity and the requirements for their implementation are discussed.

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We present a search for tau sneutrino production using the Tevatron ppbar collision data collected with the CDF II detector and corresponding to an integrated luminosity of 1 fb^-1. We focus on the scenarios predicted by the R-parity violating (RPV) supersymmetric models in which tau sneutrinos decay to two charged leptons of different flavor. With the data consistent with the standard model expectations, we set the upper limits on sigma(ppbar -> tau sneutrino)*BR(tau sneutrino ->emu,mutau,etau) and use these results to constrain the RPV couplings as a function of tau sneutrino mass.

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Abstract (Irony as object of research: Is it possible to explore what is between the lines?): The main concern of this article is the interpretation of irony: how is it brought about and how can it be investigated? The method applied is based on authentic texts and their elicited interpretations − a method referred to in this article response analysis. Interpretation of irony in the approach taken is seen as being crucially dependent on the notion of coherence. A text is perceived as being coherent if it (a) makes sense and if it(b) hangs together. Incoherent texts can result in an ironic interpretation; however, the incoherence must also be perceived as being intentional, and intentionality in turn is a sign of the edge of the ironist. Ironic interpretation is defined as a combination of five factors: (1) an ironic edge that (2) reflects the intention of the ironist, and (3) has a target and (4) a victim too. Essential to irony is its fifth factor, the fact that one or more of these four factors must be inferred from co(n)text. This definition of irony is crucial in distinguishing irony from non-irony, and it also helps to discern the differences as well as the similarities between irony and related phenomena.