27 research outputs found

    Induced-Gravity GUT-Scale Higgs Inflation in Supergravity

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    Models of induced-gravity inflation are formulated within Supergravity employing as inflaton the Higgs field which leads to a spontaneous breaking of a U(1)B-L symmetry at Mgut=2x10^16 GeV. We use a renormalizable superpotential, fixed by a U(1) R symmetry, and Kahler potentials which exhibit a quadratic non-minimal coupling to gravity with or without an independent kinetic mixing in the inflaton sector. In both cases we find inflationary solutions of Starobinsky type whereas in the latter case, others (more marginal) which resemble those of linear inflation arise too. In all cases the inflaton mass is predicted to be of the order of 10^13~GeV. Extending the superpotential of the model with suitable terms, we show how the MSSM mu parameter can be generated. Also, non-thermal leptogenesis can be successfully realized, provided that the gravitino is heavier than about 10 TeV.Comment: arXiv admin note: text overlap with arXiv:1710.05759; Final versio

    From Hybrid to Quadratic Inflation With High-Scale Supersymmetry Breaking

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    Motivated by the reported discovery of inflationary gravity waves by the BICEP2 experiment, we propose an inflationary scenario in supergravity, based on the standard superpotential used in hybrid inflation. The new model yields a tensor-to-scalar ratio r ~ 0.14 and scalar spectral index ns ~ 0.964, corresponding to quadratic (chaotic) inflation. The important new ingredients are the high-scale, (1.6-10) x 10^13 GeV, soft supersymmetry breaking mass for the gauge singlet inflaton field and a shift symmetry imposed on the K\"ahler potential. The end of inflation is accompanied, as in the earlier hybrid inflation models, by the breaking of a gauge symmetry at (1.2-7.1) x 10^16 GeV, comparable to the grand-unification scale.Comment: Version with minor corrections to appear in PL

    Upper Bound on the Tensor-to-Scalar Ratio in GUT-Scale Supersymmetric Hybrid Inflation

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    We explore the upper bound on the tensor-to-scalar ratio rr in supersymmetric (F-term) hybrid inflation models with the gauge symmetry breaking scale set equal to the value 2.861016GeV2.86\cdot10^{16} {\rm GeV}, as dictated by the unification of the MSSM gauge couplings. We employ a unique renormalizable superpotential and a quasi-canonical K\"ahler potential, and the scalar spectral index nsn_s is required to lie within the two-sigma interval from the central value found by the Planck satellite. In a sizable region of the parameter space the potential along the inflationary trajectory is a monotonically increasing function of the inflaton, and for this case, r2.9104r\lesssim2.9\cdot10^{-4}, while the spectral index running, dns/dlnk|dn_{\rm s}/d\ln k|, can be as large as 0.010.01. Ignoring higher order terms which ensure the boundedness of the potential for large values of the inflaton, the upper bound on rr is significantly larger, of order 0.010.01, for subplanckian values of the inflaton, and dns/dlnk0.006|dn_{\rm s}/d\ln k|\simeq0.006.Comment: To appear in PL

    PORT REORGANISATION AND THE WORLDS OF PRODUCTION THEORY

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    Taking into consideration the new dimensions of port production that have become evident during the resent past, this paper tackles the issue of port reorganisation. In the light of the changes in the world economy and the new competitive environment, the paper focuses on the new structures of the port industry and the characteristics of the contemporary port product within a more general analytical framework of ‘Worlds of Production’. This conceptualisation suggests that neither the industrial model of mass production, nor any other model alone, can determine a single effective pattern of organisation of port production. Within the new reality, modern ports must provide a greater variety of services to port users than in the past. The diversity and complexity of the contemporary port product demand the application of multiple organisational transformations incorporating elements from different possible action frameworks. In this vein, the introduction of intra-port competition, the development of strategic or regional networks, and the reconsideration of the role of port authority turn to critical parameters of the necessary restructuring.Port Industry, reorganisation, worlds of production theory

    The EU port policy in a historical perspective

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    This paper examines the evolution of the European Union (EU) Port Policy within a historical perspective. Analysing the changing aspects of the sectoral socio-economic context and the alterations of the institutional setting, the paper explains the slow start towards a European Port Policy (EPP), that lasted more than three decades, and then assesses why, and how, policy actors involved in the EU policy making have succeeded in carving out elements of a policy framework. The study chronicles the stages by which the EU has moved into the port policy field. Grounding on the analysis of the changing sectoral environment, the paper analyses the complex sequence of events, which have led either to legislative and political decisions or to output failures. As demonstrated by the historical analysis (1957-2004), policy integration is a dynamic, seemingly irreversible, process, which marked by the searching for a balance between liberalisation and harmonisation.peer-reviewe

    Non-Minimal Chaotic Inflation, Peccei-Quinn Phase Transition and non-Thermal Leptogenesis

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    We consider a phenomenological extension of the minimal supersymmetric standard model (MSSM) which incorporates non-minimal chaotic inflation, driven by a quadratic potential in conjunction with a linear term in the frame function. Inflation is followed by a Peccei-Quinn phase transition, based on renormalizable superpotential terms, which resolves the strong CP and mu problems of MSSM and provide masses lower than about 10^12 GeV for the right-handed (RH) (s)neutrinos. Baryogenesis occurs via non-thermal leptogenesis, realized by the out-of-equilibrium decay of the RH sneutrinos which are produced by the inflaton's decay. Confronting our scenario with the current observational data on the inflationary observables, the light neutrino masses, the baryon asymmetry of the universe and the gravitino limit on the reheat temperature, we constrain the strength of the gravitational coupling to rather large values (~45-2950) and the Dirac neutrino masses to values between about 1 and 10 GeV.Comment: Final versio

    Anatomy of F_D-Term Hybrid Inflation

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    We analyze the cosmological implications of F-term hybrid inflation with a subdominant Fayet--Iliopoulos D-term whose presence explicitly breaks a D-parity in the inflaton-waterfall sector. This scenario of inflation, which is called F_D-term hybrid model for brevity, can naturally predict lepton number violation at the electroweak scale, by tying the mu-parameter of the MSSM to an SO(3)-symmetric Majorana mass m_N, via the vacuum expectation value of the inflaton field. We show how a negative Hubble-induced mass term in a next-to-minimal extension of supergravity helps to accommodate the present CMB data and considerably weaken the strict constraints on the theoretical parameters, resulting from cosmic string effects on the power spectrum P_R. The usual gravitino overabundance constraint may be significantly relaxed in this model, once the enormous entropy release from the late decays of the ultraheavy waterfall gauge particles is properly considered. As the Universe enters a second thermalization phase involving a very low reheat temperature, which might be as low as about 0.3 TeV, thermal electroweak-scale resonant leptogenesis provides a viable mechanism for successful baryogenesis, while thermal right-handed sneutrinos emerge as new possible candidates for solving the cold dark matter problem. In addition, we discuss grand unified theory realizations of F_D-term hybrid inflation devoid of cosmic strings and monopoles, based on the complete breaking of an SU(2) subgroup. The F_D-term hybrid model offers rich particle-physics phenomenology, which could be probed at high-energy colliders, as well as in low-energy experiments of lepton flavour or number violation.Comment: 73 pages, LaTeX, minor rewordings, references added, to appear in JHE
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