7,300 research outputs found

    Transforming the European legal order: The European Court of Justice at 60+

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    The European Court of Justice has played a pivotal role in the transformation of international law obligations between Member States into an integrated legal order with direct applicability and effect in those Member States. This article explores whether or not the ECJ continues to be relevant to EU governance and integration and whether it continues to transform the legal orders of the Member States. It briefly outlines the early case law which transformed the legal order, and the preliminary reference procedure as an important element of that transformation, and then considers the extent to which the ECJ continues to act in ways which are transformational even though the legal order itself has remained relatively static. The EU citizenship jurisprudence serves as a useful example of how integration is driven forward by the Court. This article argues that the Court's decisions do continue to have significant impact on areas of law and policy and EU governance generally. It illustrates this argument using gender equality law and Human Rights as pertinent examples and concludes that the ECJ remains relevant in governance terms as it continues to drive forward EU integration in many areas and influence the development of law and policy across the Member States

    Cosmic acceleration: Inhomogeneity versus vacuum energy

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    In this essay, I present an alternative explanation for the cosmic acceleration which appears as a consequence of recent high redshift Supernova data. In the usual interpretation, this cosmic acceleration is explained by the presence of a positive cosmological constant or vacuum energy, in the background of Friedmann models. Instead, I will consider a Local Rotational Symmetric (LRS) inhomogeneous spacetime, with a barotropic equation of state for the cosmic matter. Within this framework the kinematical acceleration of the cosmic fluid or, equivalently, the inhomogeneity of matter, is just the responsible of the SNe Ia measured cosmic acceleration. Although in our model the Cosmological Principle is relaxed, it maintains local isotropy about our worldline in agreement with the CBR experiments.Comment: LATEX, 7 pags, no figs, Honorable Mention in the 1999 Essay Competition of the Gravity Research Foundatio

    What is the Homogeneity of our Universe Telling Us?

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    The universe we observe is homogeneous on super-horizon scales, leading to the ``cosmic homogeneity problem''. Inflation alleviates this problem but cannot solve it within the realm of conservative extrapolations of classical physics. A probabilistic solution of the problem is possible but is subject to interpretational difficulties. A genuine deterministic solution of the homogeneity problem requires radical departures from known physics.Comment: 6 pages. Awarded Honorable Mention in the 1999 Gravity Research Foundation Essay Competitio

    Cosmic scalar fields with flat potential

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    The dynamics of cosmic scalar fields with flat potential is studied. Their contribution to the expansion rate of the universe is analyzed, and their behaviour in a simple model of phase transitions is discussed.Comment: 9 page

    Large Scale Inhomogeneities from the QCD Phase Transition

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    We examine the first-order cosmological QCD phase transition for a large class of parameter values, previously considered unlikely. We find that the hadron bubbles can nucleate at very large distance scales, they can grow as detonations as well as deflagrations, and that the phase transition may be completed without reheating to the critical temperature. For a subset of the parameter values studied, the inhomogeneities generated at the QCD phase transition might have a noticeable effect on nucleosynthesis.Comment: 15 LaTeX pages + 6 PostScript figures appended at the end of the file, HU-TFT-94-1

    Quantum-to-classical Transition of Cosmological Perturbations for Non-vacuum Initial States

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    Transition from quantum to semiclassical behaviour and loss of quantum coherence for inhomogeneous perturbations generated from a non-vacuum initial state in the early Universe is considered in the Heisenberg and the Schr\"odinger representations, as well as using the Wigner function. We show explicitly that these three approaches lead to the same prediction in the limit of large squeezing (i.e. when the squeezing parameter rk|r_k|\to \infty): each two-modes quantum state (k, -k) of these perturbations is equivalent to a classical perturbation that has a stochastic amplitude, obeying a non-gaussian statistics which depends on the initial state, and that belongs to the quasi-isotropic mode (i.e. it possesses a fixed phase). The Wigner function is not everywhere positive for any finite rkr_k, hence its interpretation as a classical distribution function in phase space is impossible without some coarse graining procedure. However, this does not affect the transition to semiclassical behaviour since the Wigner function becomes concentrated near a classical trajectory in phase space when rk|r_k|\to \infty even without coarse graining. Deviations of the statistics of the perturbations in real space from a Gaussian one lie below the cosmic variance level for the N-particles initial states with N=N(|k|) but may be observable for other initial states without statistical isotropy or with correlations between different k modes. As a way to look for this effect, it is proposed to measure the kurtosis of the angular fluctuations of the cosmic microwave background temperature.Comment: LaTeX (28 pages),+2 eps figure

    A time varying speed of light as a solution to cosmological puzzles

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    We consider the cosmological implications of light travelling faster in the early Universe. We propose a prescription for deriving corrections to the cosmological evolution equations while the speed of light cc is changing. We then show how the horizon, flatness, and cosmological constant problems may be solved. We also study cosmological perturbations in this scenario and show how one may solve the homogeneity and isotropy problems. As it stands, our scenario appears to most easily produce extreme homogeneity, requiring structure to be produced in the Standard Big Bang epoch. Producing significant perturbations during the earlier epoch would require a rather careful design of the function c(t)c(t). The large entropy inside the horizon nowadays can also be accounted for in this scenario.Comment: To be published in Physical Review D. Note added referring to John Moffat's early work on VSL theorie

    Vacuum decay and internal symmetries

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    We study the effects of internal symmetries on the decay by bubble nucleation of a metastable false vacuum. The zero modes about the bounce solution that are associated with the breaking of continuous internal symmetries result in an enhancement of the tunneling rate into vacua in which some of the symmetries of the initial state are spontaneously broken. We develop a general formalism for evaluating the effects of these zero modes on the bubble nucleation rate in both flat and curved space-times.Comment: LaTex, 11 pages, No figures, one minor chang

    On the variable-charged black holes embedded into de Sitter space: Hawking's radiation

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    In this paper we study the Hawking evaporation of masses of variable-charged Reissner-Nordstrom and Kerr-Newman, black holes embedded into the de Sitter universe by considering the charge to be function of radial coordinate of the spherically symmetric metric.Comment: LaTex, p. 2
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