34,468 research outputs found

    Effective Supergravity from the Weakly Coupled Heterotic String

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    The motivation for Calabi-Yau-like compactifications of the weakly coupled E8E8E_8\otimes E_8 heterotic string theory, its particle spectrum and the issue of dilaton stabilization are briefly reviewed. Modular invariant models for hidden sector condensation and supersymmetry breaking are described at the quantum level of the effective field theory. Their phenomenological and cosmological implications, including a possible origin for R-parity, are discussed.Comment: 17 pages, Talk presented at the Symposium in honor of Julius Wess, Jan. 10--11, 200

    Multi-parametric solutions to the NLS equation

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    The structure of the solutions to the one dimensional focusing nonlin-ear Schr{\"o}dinger equation (NLS) for the order N in terms of quasi rational functions is given here. We first give the proof that the solutions can be expressed as a ratio of two wronskians of order 2N and then two determinants by an exponential depending on t with 2N -- 2 parameters. It also is proved that for the order N , the solutions can be written as the product of an exponential depending on t by a quotient of two polynomials of degree N (N + 1) in x and t. The solutions depend on 2N -- 2 parameters and give when all these parameters are equal to 0, the analogue of the famous Peregrine breather PN. It is fundamental to note that in this representation at order N , all these solutions can be seen as deformations with 2N -- 2 parameters of the famous Peregrine breather PN. With this method, we already built Peregrine breathers until order N = 10, and their deformations depending on 2N -- 2 parameters

    One Loop Soft Supersymmetry Breaking Terms in Superstring Effective Theories

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    We perform a systematic analysis of soft supersymmetry breaking terms at the one loop level in a large class of string effective field theories. This includes the so-called anomaly mediated contributions. We illustrate our results for several classes of orbifold models. In particular, we discuss a class of models where soft supersymmetry breaking terms are determined by quasi model independent anomaly mediated contributions, with possibly non-vanishing scalar masses at the one loop level. We show that the latter contribution depends on the detailed prescription of the regularization process which is assumed to represent the Planck scale physics of the underlying fundamental theory. The usual anomaly mediation case with vanishing scalar masses at one loop is not found to be generic. However gaugino masses and A-terms always vanish at tree level if supersymmetry breaking is moduli dominated with the moduli stabilized at self-dual points, whereas the vanishing of the B-term depends on the origin of the mu-term in the underlying theory. We also discuss the supersymmetric spectrum of O-I and O-II models, as well as a model of gaugino condensation. For reference, explicit spectra corresponding to a Higgs mass of 114 GeV are given. Finally, we address general strategies for distinguishing among these models.Comment: 49 pages: includes three tables and nine figure

    Phenomenology and cosmology of weakly coupled string theory

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    The weakly coupled vacuum of E8E8E_8\otimes E_8 heterotic string theory remains an attractive scenario for phenomenolgy and cosmology. The particle spectrum is reviewed and the issues of gauge coupling unification, dilaton stabilization and modular cosmology are discussed. A specific model for condensation and supersymmetry breaking, that respects known constraints from string theory and is phenomenologically viable, is described.Comment: 24 pages, talk presented at The Richard Arnowitt Fest, April 5-8, 1998, Texas A & M University, College Station, TX, to be published in the proceedings, full postscript available from http://phyweb.lbl.gov/theorypapers/preprints.html/41110.p

    Equity and Health

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    This article raises the problem of equity in the health system in Switzerland. Three dimensions of the concept of equity are taken into consideration: the inequality in the financing of the health system, the inequality in the distri-bution of the state of good health, and, finally, the iniquity in the access to health care. Some methodological devel-opments are presented as well as the results. In conclusion we observe that the state of good health does not depend strongly on income but that it exists some iniquity in the access to health services from specialists and that the in-come inequality is increasing due to the financing of the health system.health system; equity

    Quantum-Induced Soft Supersymmetry Breaking In Supergravity

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    We calculate the one-loop quantum contributions to soft supersymmetry breaking terms in the scalar potential in supergravity theories regulated \`a la Pauli-Villars. We find ``universal'' contributions, independent of the regulator masses and tree level soft supersymmetry breaking, that contribute gaugino masses and A-terms equal to the ``anomaly mediated'' contributions found in analyses using spurion techniques, as well as a scalar mass term not identified in those analyses. The universal terms are in general modified -- and in some cases canceled -- by model-dependent terms. Under certain restrictions on the couplings we recover the one-loop results of previous ``anomaly mediated'' supersymmetry breaking scenarios. We emphasize the model dependence of loop-induced soft terms in the potential, which are much more sensitive to the details of Planck scale physics then are the one-loop contributions to gaugino masses. We discuss the relation of our results to previous analyses.Comment: 18 pages. This replacement corrects eqs. (7) and (31) and adds clarifying comments after eq. (11) and before eq. (18
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