140 research outputs found

    Saddle point inflation from f(R)f(R) theory

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    We analyse several saddle point inflationary scenarios based on power-law f(R)f(R) models. We investigate inflation resulting from f(R)=R+αnM2(1n)Rn+αn+1M2nRn+1f(R) = R + \alpha_n M^{2(1-n)}R^n + \alpha_{n+1}M^{-2n}R^{n+1} and f(R)=nlαnM2(1n)Rnf(R) = \sum_n^l \alpha_n M^{2(1-n)} R^n as well as ll\to\infty limit of the latter. In all cases we have found relation between αn\alpha_n coefficients and checked consistency with the PLANCK data as well as constraints coming from the stability of the models in question. Each of the models provides solutions which are both stable and consistent with PLANCK data, however only in parts of the parameter space where inflation starts on the plateau of the potential, some distance from the saddle. And thus all the correct solutions bear some resemblance to the Starobinsky model.Comment: 10 pages, 8 figure

    Saddle point inflation from higher order corrections to Higgs/Starobinsky inflation

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    We explore two saddle point inflationary scenarios in the context of higher order corrections related to different generalisations of general relativity. Firstly, we deal with Jordan frame Starobinsky potential, for which we identify a portion of a parameter space of inflection point inflation, which can accommodate all the experimental results. Secondly, we analyse Higgs inflation and more specifically the influence of non-renormalisible terms on the standard quartic potential. All results were verified with the PLANCK 2015 data.Comment: 17 pages, 6 figure

    Funkcje sankcji prawnych w prawie administracyjnym – zagadnienia wybrane

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    The issue of the function of legal sanctions in the administration law is complex. It results, among others, from the possibility to understand the term “a legal sanction” in different ways. This term can be defined as a particular rule or provision, the act of application thereof, or the outcome of its execution. In practice, the issue of subject, which determines the function of particular sanctions, is also extremely significant. It can be generally said that legal sanctions in administration law can perform five functions: preventive, repressive, compelling, restrictive and redistributive

    Higher-order scalar interactions and SM vacuum stability

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    Investigation of the structure of the Standard Model effective potential at very large field strengths opens a window towards new phenomena and can reveal properties of the UV completion of the SM. The map of the lifetimes of the vacua of the SM enhanced by nonrenormalizable scalar couplings has been compiled to show how new interactions modify stability of the electroweak vacuum. Whereas it is possible to stabilize the SM by adding Planck scale suppressed interactions and taking into account running of the new couplings, the generic effect is shortening the lifetime and hence further destabilisation of the SM electroweak vacuum. These findings have been illustrated with phase diagrams of modified SM-like models. It has been demonstrated that stabilisation can be achieved by lowering the suppression scale of higher order operators while picking up such combinations of new couplings, which do not deepen the new minima of the potential. Our results show the dependence of the lifetime of the electroweak minimum on the magnitude of the new couplings, including cases with very small couplings (which means very large effective suppression scale) and couplings vastly different in magnitude (which corresponds to two different suppression scales).Comment: plain Latex, 9 figure

    Implications of extreme flatness in a general f(R) theory

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    We discuss a modified gravity theory defined by f(R)=nlαnM2(1n)Rnf(R) = \sum_{n}^{l} \alpha_n M^{2(1-n)} R^n. We consider both finite and infinite number of terms in the series while requiring that the Einstein frame potential of the theory has a flat area around any of its stationary points. We show that the requirement of maximally flat stationary point leads to the existence of the saddle point (local maximum) for even (odd) ll. In both cases for ll\to\infty one obtains the Starobinsky model with small, exponentially suppressed corrections. Besides the GR minimum the Einstein frame potential has an anti de Sitter vacuum. However we argue that the GR vacuum is absolutely stable and AdS cannot be reached neither via classical evolution nor via quantum tunnelling. Our results show that a Starobinsky-like model is the only possible realisation of f(R)f(R) theory with an extremely flat area in the Einstein frame potential.Comment: 13 pages, 4 figure
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