36,315 research outputs found

    Local ζ\zeta-functions, stress-energy tensor, field fluctuations, and all that, in curved static spacetime

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    This is a quick review on some technology concerning the local zeta function applied to Quantum Field Theory in curved static (thermal) spacetime to regularize the stress-energy tensor and the field fluctuations.Comment: LaTeX 10 Pages. Submitted to the volume "Cosmology, Quantum Vacuum, and Zeta Functions", in honour of Professor Emilio Elizalde on the occasion of his 60th birthda

    Inflation targeting and product market deregulation : [Version Januar 2012]

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    I evaluate the effect of inflation targeting on inflation and how it interacts with product market deregulation during the disinflationary process in the 1990s. Using a sample of 21 OECD countries, I show that, after controlling for product market deregulation, the effect of inflation targeting is quantitatively important and statistically significant. Moreover, product market deregulation also matters in particular in countries that adopted an inflation targeting regime. I propose a New Keynesian Phillips curve with an explicit role for market deregulation to rationalize the empirical evidence

    Proof of the symmetry of the off-diagonal Hadamard/Seeley-deWitt's coefficients in CC^{\infty} Lorentzian manifolds by a local Wick rotation

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    Completing the results obtained in a previous paper, we prove the symmetry of Hadamard/Seeley-deWitt off-diagonal coefficients in smooth DD-dimensional Lorentzian manifolds. To this end, it is shown that, in any Lorentzian manifold, a sort of ``local Wick rotation'' of the metric can be performed provided the metric is a locally analytic function of the coordinates and the coordinates are ``physical''. No time-like Killing field is necessary. Such a local Wick rotation analytically continues the Lorentzian metric in a neighborhood of any point, or, more generally, in a neighborhood of a space-like (Cauchy) hypersurface, into a Riemannian metric. The continuation locally preserves geodesically convex neighborhoods. In order to make rigorous the procedure, the concept of a complex pseudo-Riemannian (not Hermitian or K\"ahlerian) manifold is introduced and some features are analyzed. Using these tools, the symmetry of Hadamard/Seeley-deWitt off-diagonal coefficients is proven in Lorentzian analytical manifolds by analytical continuation of the (symmetric) Riemannian heat-kernel coefficients. This continuation is performed in geodesically convex neighborhoods in common with both the metrics. Then, the symmetry is generalized to CC^\infty non analytic Lorentzian manifolds by approximating Lorentzian CC^{\infty} metrics by analytic metrics in common geodesically convex neighborhoods. The symmetry requirement plays a central r\^{o}le in the point-splitting renormalization procedure of the one-loop stress-energy tensor in curved spacetimes for Hadamard quantum states.Comment: 30 pages, LaTeX, no figures, shortened version, minor errors corrected a note added. To appear in Commun. Math. Phy

    Ways in which coherence is confirmation conducive

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    Recent works in epistemology show that the claim that coherence is truth conducive – in the sense that, given suitable ceteris paribus conditions, more coherent sets of statements are always more probable – is dubious and possibly false. From this, it does not follows that coherence is a useless notion in epistemology and philosophy of science. Dietrich and Moretti 2005 have proposed a formal of account of how coherence is confirmation conducive – that is, of how the coherence of a set of statements facilitates the confirmation of such statements. This account is grounded in two confirmation transmission properties that are satisfied by some of the measures of coherence recently proposed in the literature. These properties explicate everyday and scientific uses of coherence. In his paper, I review the main findings of Dietrich and Moretti 2005 and define two evidence gathering properties that are satisfied by the same measures of coherence and constitute further ways in which coherence is confirmation conducive. At least one of these properties vindicates important applications of the notion of coherence in everyday life and in science

    Transparency and emerging market bond spreads : [Version June 2011]

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    I investigate the effect of transparency on the borrowing costs of Emerging Markets Economies. Transparency is measured by whether or not the countries publish the IMF Article IV Staff report and the Reports on the Observance of Standards and Codes (ROSC). Using difference-in-difference estimation, I study the effect on the sovereign credit spreads for 18 Emerging Market Economies over the period 1999-2007. I show that the effect of publishing the Article IV reports is negligible while publishing the ROSC matters, leading to a reduction in the spreads of over 15% in the samples 1999-2006 and 1999-2007. JEL Classification: F33, F34, G15 Keywords: Sovereign Bond Markets, Transparency, Emerging Market Economie