18,527 research outputs found

    geography of inequalities in Europe.

    Get PDF
    This paper analyses some of the theoretical and empirical arguments that serve to legitimate regional policies in Europe. We start by reviewing the existing evidence that European integration has led to a process of convergence between countries but not between regions inside countries and suggest some mechanisms through which this can happen. Taking the example of France, we show that in the past twenty years regional divergence in production has indeed occurred. However, the geography of incomes has, during the same period, become more equal producing a “scissors effect” between the geographies of production and income. This suggests that transfers, which have nothing to do with regional policies, have, at least in France, more than compensated the increase in production inequality. Hence, “regional convergence” is not a synonym of “regional cohesion” at least at the national level. We then review evidence on a possible trade-off between growth and regional inequalities to suggest that efficiency motives can not easily be used to defend regional policies. Both evidence and theory suggest that regional concentration leads to efficiency gains. This also implies that the EU is faced with a choice it has tried to avoid until now. Either, it puts its effort in slowing or even reversing the process of spatial economic concentration at the national level or it concentrates on policies to speed up the convergence process between poor and rich countries. Finally, we analyse the relation between spatial and social inequalities. We report empirical evidence for Europe that suggests a strong empirical relation between the two: even after controlling for transfers and other possible determinants of individual inequalities, we find that countries with more regional inequalities are also those with more individual inequalities.Economic geography;regional inequalities;regional subsidies;

    High Energy Physics and Quintessence

    Get PDF
    It is shown that any realistic model of quintessence should be based on Supergravity (SUGRA) since the value of the quintessence field on the attractor is approximately the Planck mass. Under very general assumptions, the typical shape of a SUGRA tracking potential is derived. Cosmological implications are investigated. In particular, it is demonstrated that, generically, the equation of state parameter is driven to a value close to -1 in agreement with recent observations.Comment: 4 pages, 2 figures. Contribution to the Proceedings of Moriond 2000 "Energy Densities in the Universe", Les Arcs, France, January 22-29 200

    Dark Energy and the MSSM

    Get PDF
    We consider the coupling of quintessence to observable matter in supergravity and study the dynamics of both supersymmetry breaking and quintessence in this context. We investigate how the quintessence potential is modified by supersymmetry breaking and analyse the structure of the soft supersymmetry breaking terms. We pay attention to their dependence on the quintessence field and to the electroweak symmetry breaking, ie the pattern of fermion masses at low energy within the Minimal Supersymmetric Standard Model (MSSM) coupled to quintessence. In particular, we compute explicitly how the fermion masses generated through the Higgs mechanism depend on the quintessence field for a general model of quintessence. Fifth force and equivalence principle violations are potentially present as the vacuum expectation values of the Higgs bosons become quintessence field dependent. We emphasize that equivalence principle violations are a generic consequence of the fact that, in the MSSM, the fermions couple differently to the two Higgs doublets. Finally, we also discuss how the scaling of the cold dark and baryonic matter energy density is modified and comment on the possible variation of the gauge coupling constants, among which is the fine structure constant, and of the proton-electron mass ratioComment: 26 pages, minor corrections, typos correcte

    Moduli Fields as Quintessence and the Chameleon

    Get PDF
    We consider models where moduli fields are not stabilized and play the role of quintessence. In order to evade gravitational tests, we investigate the possibility that moduli behave as chameleon fields. We find that, for realistic moduli superpotentials, the chameleon effect is not strong enough, implying that moduli quintessence models are gravitationally ruled out. More generally, we state a no-go theorem for quintessence in supergravity whereby models either behave like a pure cosmological constant or violate gravitational testsComment: 11 pages, 1 figur
    • 

    corecore