2,873 research outputs found

    Flat direction condensate instabilities in the MSSM

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    Coherently oscillating scalar condensates formed along flat directions of the MSSM scalar potential are unstable with respect to spatial perturbations if the potential is flatter than phi^2, resulting in the formation of non-topological solitons such as Q-balls. Using renormalization group we calculate the corrections to the phi^2 potential for a range of flat directions and show that unstable condensates are a generic feature of the MSSM. Exceptions arise for an experimentally testable range of stop and gluino masses when there are large admixtures of stops in the flat direction scalar.Comment: 9 pages, 9 encapsulated postscript figure

    Inflation in large N limit of supersymmetric gauge theories

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    Within supersymmetry we provide an example where the inflaton sector is derived from a gauge invariant polynomial of SU(N) or SO(N) gauge theory. Inflation in our model is driven by multi-flat directions, which assist accelerated expansion. We show that multi-flat directions can flatten the individual non-renormalizable potentials such that inflation can occur at sub-Planckian scales. We calculate the density perturbations and the spectral index, we find that the spectral index is closer to scale invariance for large N. In order to realize a successful cosmology we require large N of order, N~600.Comment: 10 pages, LaTeX2e, misprints corrected, version accepted for publishin

    Simulations of Q-Ball Formation

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    The fragmentation of the Affleck-Dine condensate is studied by utilizing 3+1 dimensional numerical simulations. The 3+1 dimensional simulations confirm that the fragmentation process is very similar to the results obtained by 2+1 dimensional simulations. We find, however, that the average size of Q-balls in 3+1 dimensions is somewhat larger that in 2+1 dimensions. A filament type structure in the charge density is observed during the fragmentation process. The resulting final Q-ball distribution is strongly dependent on the initial conditions of the condensate and approaches a thermal one as the energy-charge ratio of the Affleck-Dine condensate increases.Comment: 9 pages, 8 figures; corrected typos (v2,v3

    Recent progress in Affleck-Dine baryogenesis

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    In the MSSM, cosmological scalar field condensates formed along flat directions of the scalar potential (Affleck-Dine condensates) are typically unstable with respect to formation of Q-balls, a type of non-topological soliton. I discuss the creation and growth of the quantum seed fluctuations which catalyse the collapse of the condensate. In D-term inflation models, the fluctuations of squark fields in the flat directions also give rise to isocurvature density fluctuations stored in the Affleck-Dine condensate. After the condensate breaks up, these can be perturbations in the baryon number, or, in the case where the present neutralino density comes directly from B-ball decay, perturbations in the number of dark matter neutralinos. The latter case results in a large enhancement of the isocurvature perturbation, which should be observable by PLANCK.Comment: 8 pages, 2 figures; invited talk at COSMO9
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