1,515 research outputs found
Dependence of the Higgs coupling hMS(M) on mH and the possible onset of new physics
No full textThe simple renormalization framework previously discussed by one of us is extended to treat the Higgs potential of the standard model. As an application, we obtain in a straightforward manner the one-loop correction δ(M) in the natural relation h(M) = √ 1 2 GμmH2[1 + δ(M)], where mH is the physical mass of the Higgs boson, Gμ the accurately known μ decay coupling constant and h(M) the MS quartic Higgs coupling at mass scale M. The correction δ(M) contains contributions proportional to ξ ≡ mH2/mZ2 and ξ-1 and become large for ξ≫1 or ξ≪1. The dependence of h(M) on M and mH is analyzed by combining our one-loop results (which provide initial conditions) and approximate analytic solutions of relevant renormalization group equations. A parameter Mc, which roughly describes the mass scale at which perturbation theory breaks down and the possible onset of new physics, is discussed as a function of mH. © 1986
Measuring Vulnerability to Poverty Using Long-Term Panel Data
No full textMeasuring Vulnerability to Poverty Using Long-Term Panel Data Author & abstract Download & other version 16 References 4 Citations Related works & more Corrections Author Listed: Katja Landau (Georg-August-University Göttingen) Stephan Klasen (Georg-August-University Göttingen) Walter Zucchini (Georg-August-University Göttingen) Registered: Stephan Klasen Abstract We investigate the accuracy of ex ante assessments of vulnerability to income poverty using cross-sectional data and panel data. We use long-term panel data from Germany and apply di fferent regression models, based on household covariates and previous-year equivalence income, to classify a household as vulnerable or not. Predictive performance is assessed using the Receiver Operating Characteristics (ROC), which takes account of false positive as well as true positive rates. Estimates based on cross-sectional data are much less accurate than those based on panel data, but for Germany, the accuracy of vulnerability predictions is limited even when panel data are used. In part this low accuracy is due to low poverty incidence and high mobility in and out of poverty
Measuring Vulnerability to Poverty Using Long-Term Panel Data
No full textMeasuring Vulnerability to Poverty Using Long-Term Panel Data Author & abstract Download & other version 16 References 4 Citations Related works & more Corrections Author Listed: Katja Landau (Georg-August-University Göttingen) Stephan Klasen (Georg-August-University Göttingen) Walter Zucchini (Georg-August-University Göttingen) Registered: Stephan Klasen Abstract We investigate the accuracy of ex ante assessments of vulnerability to income poverty using cross-sectional data and panel data. We use long-term panel data from Germany and apply di fferent regression models, based on household covariates and previous-year equivalence income, to classify a household as vulnerable or not. Predictive performance is assessed using the Receiver Operating Characteristics (ROC), which takes account of false positive as well as true positive rates. Estimates based on cross-sectional data are much less accurate than those based on panel data, but for Germany, the accuracy of vulnerability predictions is limited even when panel data are used. In part this low accuracy is due to low poverty incidence and high mobility in and out of poverty
Does policy stability increase the Constitutional court’s independence? : the case of Italy during the First Republic (1956-1992)
No full textIn this paper, we consider the sentences of constitutional illegitimacy by the Italian Constitutional Court in the First Republic (1956–1992) as a measure of its independence from politicians. We focus on the Court's incidental review and test whether the Court's independence increases when there is more policy stability, namely when politicians are less able to change the policy status quo by legislation. We follow Tsebelis (2002) in assuming that legislative policy change is less likely when either the number and/or ideological distance of veto players increases. As a proxy for the size of the veto players' Pareto set, we use either the number of parties in government, or the number of parties forming a constitutional majority in Parliament, or the number of effective parties in Parliament, or measures of ideological distance based on Laver and Hunt (1992). By controlling for the Court's degree of internal cohesion, cointegration analysis shows that there is a stable and positive long-run relationship between the Court's independence and proxy measures of the degree of policy stability
Wilson Surfaces for Surface Knots: A Field Theoretic Route to Higher Knots
No full textHolonomy invariants in strict higher gauge theory have been studied in depth aiming to applications to higher Chern–Simons theory. For a flat 2–connection, the holonomy of surface knots of arbitrary genus has been defined and its covariance properties under 1–gauge transformation and change of base data have been determined. Using quandle theory, a definition of trace over a crossed module such to yield surface knot invariants upon application to 2–holonomies has been given
Damages induced by an over-the-row harvester in ten cultivars in a high-density olive orchard
No full textThe damages induced by an over-the-row harvester were studied in 10 olive cultivars in a high-density orchard (1,250 trees ha-1) planted in 2011 in Central Italy. ‘Maurino’, ‘Sargano di Fermo’, ‘Ascolana tenera’, ‘Rosciola’, ‘Piantone di Mogliano’, ‘Piantone di Falerone’, ‘Arbequina’, ‘Tosca®’, ‘Don Carlo®’ and ‘FS17®’ were harvested by a tow-behind machine in 3 consecutive years (2015, 2016 and 2017). Trees were pruned with an initial conical shape since planting, removing long branches perpendicularly to the row to create a continuous hedgerow system finally. The canopy height ranged from 2.88±0.32 m to 3.3±0.20 m, and the transversal diameter (perpendicular to the row) from 1.78±0.24 m to 2.4±0.20 m in 2016 and 2018, respectively. The damages (hurts and breakings) were monitored in 20 homogeneous trees per cultivar at the end of the harvest. ‘Maurino’ and ‘Arbequina’ were averagely less damaged than the other studied cultivars, whereas ‘FS17®’ showed more hurt and breakings. The growth of the canopy during the three years increased the susceptibility to limb breakage of most part of the cultivars. Results are discussed to identify most and least damaged cultivars and to detect architectural predictors to classify them according to their susceptibility to damage. This study supplies useful information on the adaptability of local, national, and international olive cultivars to high density plantations and their suitability and specific needs for over-the-row mechanical harvest
Legislative output and the Constitutional Court in Italy
No full textThis paper considers the impact of the Constitutional Court on legislative output in Italy. Following Tsebelis’ ((2002) Veto Players: Foundations of Institutional Analysis. Princeton: Princeton University Press) veto players model and the stylised facts as regards the Italian Constitutional Court’s activity, this paper presents a multi-stage game in the spirit of Gely and Spiller ((1990). A rational choice theory of supreme court statutory decisions with applications to the state farm and grove city cases. Journal of Law, Economics, and Organization 6, 263–300). In the first stage, the legislative veto players, namely the parties in government, choose whether to change or not the policy status quo by enacting new legislation. In the second stage, the Court makes a constitutional interpretation: it decides whether to alter or not the outcome of the first stage through a sentence of constitutional illegitimacy. The Court has both the power of annulling laws and a limited power of creating new legally binding norms. Moreover, in the third stage, a constitutional law voted by a parliamentary qualified majority can overturn the Court’s decisions. The model predicts that the presence of the Court lowers legislative policy change and tests this prediction with 1956–2001 annual time series data for Italy. Copyright Springer Science+Business Media, LLC 2006Veto players, Constitutional Court, Legislative output, Italy, D72,
The Lie algebroid Poisson sigma model
No full textThe Poisson-Weil sigma model, worked out by the author, stems from gauging a Hamiltonian Lie group symmetry of the target space of the Poisson sigma model. Upon gauge fixing of the BV master action, it yields interesting topological field theories such as the 2-dimensional Donaldson-Witten topological gauge theory and the gauged A topological sigma model. In this paper, generalizing the above construction, we construct the Lie algebroid Poisson sigma model. This is yielded by gauging a Hamiltonian Lie groupoid symmetry of the Poisson sigma model target space. We use the BV quantization approach in the AKSZ geometrical version to ensure consistent quantization and target space covariance. The model has an extremely rich geometry and an intricate BV cohomology, which are studied in detail
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