5,359 research outputs found

    Dark Matter Prediction from Canonical Quantum Gravity with Frame Fixing

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    We show how, in canonical quantum cosmology, the frame fixing induces a new energy density contribution having features compatible with the (actual) cold dark matter component of the Universe. First we quantize the closed Friedmann-Robertson-Walker (FRW) model in a sinchronous reference and determine the spectrum of the super-Hamiltonian in the presence of ultra-relativistic matter and a perfect gas contribution. Then we include in this model small inhomogeneous (spherical) perturbations in the spirit of the Lemaitre-Tolman cosmology. The main issue of our analysis consists in outlining that, in the classical limit, the non-zero eigenvalue of the super-Hamiltonian can make account for the present value of the dark matter critical parameter. Furthermore we obtain a direct correlation between the inhomogeneities in our dark matter candidate and those one appearing in the ultra-relativistic matter.Comment: 5 pages, to appear on Modern Physics Letters

    Dissipation Instability in the Accretion Disk

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    The model of a geometrically thin gaseous disk in the external gravitational potential is considered. The dinamics of small nonaxisymmetric perturbations in the plane of the accretion disk with dissipative effects is investigated. It is showed, that conditions of development and parameters of unstable oscillation modes in the opticaly thick accretion disk are strongly depended on the models of viscosity and opacity.Comment: Plain TeX, 6 pages, 2 figures (GIF), Submitted to Astron. Astrophys. Transaction

    Foreign Direct Investment and Regional Development in Romania

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    The regional integration of the Romanian economy implies the continuation of modernizing existent structures, expanding the new entrepreneurial culture and foster the individual competences for corresponding to the European model. Foreign direct investments represent the link between financial and productive systems, integrating them at a regional and global level. Beside the imported capital flows, they have a direct impact upon the management of the productive entities, assure a transfer of modern technologies, increase the level of occupation and the household available income, modifying the consumers culture. The regional development policy must ensure the reduction of disparities between the different levels of development of the Romanian regions through encouraging foreign direct investment capable of completing the little dimension of the local capital. Taking into consideration the movement of disparities to East and the fact that the increase of economical development disparity after the last two European Union enlargements did not involve a higher level of allocated funds, foreign direct investments remain an alternative for the disparity elimination and accelerating the restructuring marked by the globalizationregional development, socio-economical disparities, foreign direct investments

    The SMEs Performances Explained Through Influences of the Economic Context. Study Case: Romania

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    Small and medium-sized enterprises (SMEs) are the most dynamic and vital factor of progress in the contemporary society, main generator of economic performance and substance in any country, employment opportunity provider for most of population, major contributor to the national budget, and engine to improve the living standard of the population. SMEs represent 99% from all enterprises, drawing up the main human resource agglomeration. The higher flexibility of SMEs, the permanent contact of the entrepreneur with the organization, the capacity of producing goods and services to satisfy different needs and demands, the organizational environment favourable to change and innovation represent the elements that explain higher performance of the SMEs sector.small and medium-sized enterprises, macroeconomic indicators, performances, Romania.

    Metabolisme i evolució: el llenguatge matemàtic de la teoria de catàstrofes

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    Динамика младенческой смертности в Белгородской области

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    Представлен анализ младенческой смертности в Белгородской области. Приведена статистика по Российской Федерации. Была проанализирована связь между введением в эксплуатацию специализированных учреждений, а также кадровыми решениями и изменением динамики младенческой смертност

    ANALISIS TENTANG PERSEPSI SOCIAL MEDIA MARKETING, KAMPANYE VIRAL MARKETING, DAN DINAMIKA VIRTUAL BRAND COMMUNITY PADA FITUR SPONSOR INSTAGRAM TERHADAP PEMBENTUKAN BRAND AWARENESS ADIDAS

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    Digitalization era of social media is now used as a tool for advertising. Where Instagram had established sponsors feature like Facebook ads. Starting from declining issues from adidas which created a research question: “How does instagram sponsors feature shaped brand awareness of Adidas?” This study uses four variables: social media marketing perception, viral marketing campaign, and dinamics of virtual brand community to affected brand awareness. This research hypothesis testing using the data of 130 respondents. The analysis technique used in this research is to use a software program Statistical Package for Social Science (SPSS). The result of this study indicate social media marketing perception, viral marketing campaign, and dinamics of virtual brand community are positively affect to brand awareness

    Final measurement of Bs0B^0_s mixing phase in the full CDF Run II data set

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    We report the final CDF measurement of the Bs0B^0_s mixing phase, mean lifetime, and decay-width difference through the fit of the time evolution of flavor-tagged Bs0J/ψϕB^0_s \rightarrow J/\psi \phi decays. The measurement is based on the full data set of 1.96 TeV ppˉp\bar{p} collisions collected between February 2002 and September 2011 by the CDF experiment. The results are consistent with the standard model and other experimental determinations and are amongst the most precise to date.Comment: 3 pages, 2 figures, conference IFAE 201
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