2,865 research outputs found

    Isotropy of the early universe from CMB anisotropies

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    The acoustic peak in the CMB power spectrum is sensitive to causal processes and cosmological parameters in the early universe up to the time of last scattering. We provide limits on correlated spatial variations of the peak height and peak position and interpret these as constraints on the spatial variation of the cosmological parameters (baryon density, cold dark matter density and cosmological constant as well as the amplitude and tilt of the original fluctuations). We utilize recent work of Hansen, Banday and Gorski (HBG) who have studied the spatial isotropy of the power spectrum as measured by WMAP by performing the power spectrum analysis on smaller patches of the sky. We find that there is no statistically significant correlated asymmetry of the peak. HBG have also provided preliminary indications of a preferred direction in the lower angular momentum range(~ 2-40) and we show how possible explanations of this asymmetry are severely constrained by the data on the acoustic peak. Finally we show a possible non-gaussian feature in the data, associated with a difference in the northern and southern galactic hemispheres.Comment: 14 pages, 3 figures, v.2 adds an extra relevant reference and commen

    The elusive quest for balanced regional growth from Barlow to Brexit: lessons from partitioning regional employment growth in Great Britain

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    The British Government’s economic strategy for post-Brexit Britain of achieving balanced regional growth by “driving growth across the whole country” echoes the objectives set by the Barlow Report of 1940. The regional policies that followed the Barlow Report were heavily influenced by papers written for the Commission by G D A (later Sir Donald) MacDougall. The first of these papers was included as an appendix to the report itself and introduced the shift-share methodology to the analysis of regional employment growth, and subsequently shown to be flawed. The second paper considered the urban hierarchy and growth but was never fully developed. Consequently post-war regional policy focussed on the contribution of industrial structure to employment growth without fully taking into account the urban hierarchy or regional locations of that employment. This article replaces the flawed shift-share methodology with multifactor partitioning (MFP) and applies it to regional employment growth for the period 1971-2012, a span of special interest because it largely coincides with British membership of the European Union (EU). The deficiencies in the second paper are addressed by introducing allometry to measure the employment growth of each region relative to that of Great Britain and then regression analysis to relate the allometries to distance from London. The results of the two sets of analyses highlight the need for a multiple-factor, comprehensive, and integrated approach to regional policy and provide a benchmark against which to gauge the success of Britain's post-Brexit policy of driving future growth across the whole country

    Baryon Masses in Chiral Perturbation Theory with Infrared Regularization

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    The baryon masses are examined in SU(3) chiral perturbation theory to third order using the recently proposed infrared regularization scheme. Fourth order is estimated by evaluating the dominant diagram. With this regularization the magnitude of the loop integrals is reduced so that the convergence of the series appears to be better than in the heavy baryon approach.Comment: The original third order calculation is supplemented by an estimate of fourth order using just the dominant diagram. The convergence still appears to be better than in the heavy baryon approach. To be published in Phys. Rev. C. 15 pages latex, 2 postscript figure

    A Newtonian Model for the Quantum Gravitational Back-Reaction on Inflation

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    Quantum gravitational back-reaction offers a simultaneous explanation for why the cosmological constant is so small and a natural model of inflation in which scalars play no role. In this talk I review previous work and present a simple model of the mechanism in which the induced stress tensor behaves like negative vacuum energy with a density proportional to Λ/8πG(GΛ)2Ht-\Lambda/{8\pi G} \cdot (G \Lambda)^2 \cdot H t. The model also highlights the essential role of causality in back-reaction.Comment: 4 pages, LaTeX 2.6, no figures. Talk given at the International Meeting on Quantum Gravity and Spectral Geometry, Naples, Italy, July 2-7, 200

    Publication Trends in North-Eastern Indian Multi-Disciplinary Journal: A Content Analysis of Man and Society

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    Journal analysis has been an important tool to understand various facets of academic publishing trends. A content analysis of research published in Man and Society: A Journal of North-East Studies was conducted for Volumes I through XIV. A total of 20 issues of the bi-annually published journal were analyzed involving the placement of 116 articles in 9 substantive content categories revealing information about the authorship, types of research conducted as well as areas of research focus. In addition, the study has also examined the types and locations of institutions the authors are affiliated with. This has been done with a broad view to examine research focus and trends in the journal as a lens to understanding broader perspectives in scholarship and research in the Northeastern region. The findings indicate that the journal has stayed true to its mission of publishing articles across various disciplines pertaining to multiple issues of North-East India

    Publication Trends in North-Eastern Indian Multi-Disciplinary Journal: A Content Analysis of Man and Society

    Get PDF
    Journal analysis has been an important tool to understand various facets of academic publishing trends. A content analysis of research published in Man and Society: A Journal of North-East Studies was conducted for Volumes I through XIV. A total of 20 issues of the bi-annually published journal were analyzed involving the placement of 116 articles in 9 substantive content categories revealing information about the authorship, types of research conducted as well as areas of research focus. In addition, the study has also examined the types and locations of institutions the authors are affiliated with. This has been done with a broad view to examine research focus and trends in the journal as a lens to understanding broader perspectives in scholarship and research in the Northeastern region. The findings indicate that the journal has stayed true to its mission of publishing articles across various disciplines pertaining to multiple issues of North-East India

    Final state rescattering as a contribution to BργB \to \rho \gamma

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    We provide a new estimate of the long-distance component to the radiative transition BργB \to \rho \gamma. Our mechanism involves the soft-scattering of on-shell hadronic products of nonleptonic BB decay, as in the chain BρρργB \to \rho\rho \to \rho\gamma. We employ a phenomenological fit to scattering data to estimate the effect. The specific intermediate states considered here modify the BργB \to \rho \gamma decay rate at roughly the 585 \to 8% level, although the underlying effect has the potential to be larger. Contrary to other mechanisms of long distance physics which have been discussed in the literature, this yields a non-negligible modification of the B0ρ0γB^0 \to \rho^0 \gamma channel and hence will provide an uncertainty in the extraction of VtdV_{td}. This mechanism also affects the isospin relation between the rates for BργB^- \to \rho^-\gamma and B0ρ0γB^0 \to \rho^0 \gamma and may generate CP asymmetries at experimentally observable levels.Comment: 15 pages, RevTex, 3 figure

    Photon-Photon Scattering, Pion Polarizability and Chiral Symmetry

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    Recent attempts to detect the pion polarizability via analysis of γγππ\gamma\gamma\rightarrow\pi\pi measurements are examined. The connection between calculations based on dispersion relations and on chiral perturbation theory is established by matching the low energy chiral amplitude with that given by a full dispersive treatment. Using the values for the polarizability required by chiral symmetry, predicted and experimental cross sections are shown to be in agreement.Comment: 21 pages(+10 figures available on request), LATEX, UMHEP-38

    Cosmological Consequences of String Axions

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    Axion fluctuations generated during inflation lead to isocurvature and non-Gaussian temperature fluctuations in the cosmic microwave background radiation. Following a previous analysis for the model independent string axion we consider the consequences of a measurement of these fluctuations for two additional string axions. We do so independent of any cosmological assumptions except for the axions being massless during inflation. The first axion has been shown to solve the strong CP problem for most compactifications of the heterotic string while the second axion, which does not solve the strong CP problem, obeys a mass formula which is independent of the axion scale. We find that if gravitational waves interpreted as arising from inflation are observed by the PLANCK polarimetry experiment with a Hubble constant during inflation of H_inf \apprge 10^13 GeV the existence of the first axion is ruled out and the second axion cannot obey the scale independent mass formula. In an appendix we quantitatively justify the often held assumption that temperature corrections to the zero temperature QCD axion mass may be ignored for temperatures T \apprle \Lambda_QCD.Comment: 27 pages, 4 figures; v2: References corrected; v3: Assumptions simplified, minor corrections, conclusions unchange

    On the Ultraviolet Behaviour of Newton's constant

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    We clarify a point concerning the ultraviolet behaviour of the Quantum Field Theory of gravity, under the assumption of the existence of an ultraviolet Fixed Point. We explain why Newton's constant should to scale like the inverse of the square of the cutoff, even though it is technically inessential. As a consequence of this behaviour, the existence of an UV Fixed Point would seem to imply that gravity has a built-in UV cutoff when described in Planck units, but not necessarily in other units.Comment: 8 pages; CQG class; minor changes and rearrangement
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