1,361 research outputs found

    Gauge algebra of irreducible theories in the Sp(2)-symmetric BRST formalism

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    An explicit solution to classical master equations of the Sp(2)-symmetric Hamiltonian BRST quantization scheme is presented in the case of irreducible gauge theories. A realization of the observable algebra is constructed.Comment: 12 pages, v2: typos corrected, an explicit formula and references adde

    Generalized BRST Quantization and Massive Vector Fields

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    A previously proposed generalized BRST quantization on inner product spaces for second class constraints is further developed through applications. This BRST method involves a conserved generalized BRST charge Q which is not nilpotent but which satisfies Q=\delta+\delta^{\dagger}, \delta^2=0, and by means of which physical states are obtained from the projection \delta|ph>=\delta^{\dagger}|ph>=0. A simple model is analyzed in detail from which some basic properties and necessary ingredients are extracted. The method is then applied to a massive vector field. An effective theory is derived which is close to the one of the Stueckelberg model. However, since the scalar field here is introduced in order to have inner product solutions, a massive Yang-Mills theory with polynomial interaction terms might be possible to construct.Comment: 19 pages,Latexfil

    Government Expenditure, Foreign Direct Investment and Economic Growth in Nigeria

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    Government expenditure and Foreign Direct Investment (FDI) are vital macroeconomic variables of any economy as they are strong propellant of economic growth. The need to control and monitoring government spending and the FDI so as to achieve a steady economic growth necessitated this study. The study seeks to determine the impact of government expenditure and FDI on the Nigeria economic growth. A multiple regression analysis was used to test the relationship between government expenditure (capital and recurrent expenditure) and FDI as the explanatory variables on GDP (proxy for economic growth) as the dependent variable. Our result revealed that the explanatory variables: CEXP, REXP and FDI had significant relationship with economic growth. However CEXP did not conform to expectation. Some recommendations such as a thorough and accountable management of capital and recurrent expenditures in Nigeria, adequate planning, an effective macroeconomic framework and conducive economic environment to encourage foreign direct investment is require

    Gauge Consistent Wilson Renormalization Group II: Non-Abelian Case

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    We give a wilsonian formulation of non-abelian gauge theories explicitly consistent with axial gauge Ward identitities. The issues of unitarity and dependence on the quantization direction are carefully investigated. A wilsonian computation of the one-loop QCD beta function is performed.Comment: 34 pages, 1 eps figure, latex2e. Minor changes, version to appear in Int. J. Mod. Phy

    The Hot Bang state of massless fermions

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    In 2002, a method has been proposed by Buchholz et al. in the context of Local Quantum Physics, to characterize states that are locally in thermodynamic equilibrium. It could be shown for the model of massless bosons that these states exhibit quite interesting properties. The mean phase-space density satisfies a transport equation, and many of these states break time reversal symmetry. Moreover, an explicit example of such a state, called the Hot Bang state, could be found, which models the future of a temperature singularity. However, although the general results carry over to the fermionic case easily, the proof of existence of an analogue of the Hot Bang state is not quite that straightforward. The proof will be given in this paper. Moreover, we will discuss some of the mathematical subtleties which arise in the fermionic case.Comment: 17 page

    The Reeh-Schlieder property for thermal field theories

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    We show that the Reeh-Schlieder property w.r.t. the KMS-vector is a direct consequence of locality, additivity and the relativistic KMS-condition. The latter characterises the thermal equilibrium states of a relativistic quantum field theory. The statement remains vaild even if the given equilibrium state breaks spatial translation invariance.Comment: plain tex, 10 page

    Recent Developments in Enantioselective Transition Metal Catalysis Featuring Attractive Noncovalent Interactions between Ligand and Substrate.

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    Enantioselective transition metal catalysis is an area very much at the forefront of contemporary synthetic research. The development of processes that enable the efficient synthesis of enantiopure compounds is of unquestionable importance to chemists working within the many diverse fields of the central science. Traditional approaches to solving this challenge have typically relied on leveraging repulsive steric interactions between chiral ligands and substrates in order to raise the energy of one of the diastereomeric transition states over the other. By contrast, this Review examines an alternative tactic in which a set of attractive noncovalent interactions operating between transition metal ligands and substrates are used to control enantioselectivity. Examples where this creative approach has been successfully applied to render fundamental synthetic processes enantioselective are presented and discussed. In many of the cases examined, the ligand scaffold has been carefully designed to accommodate these attractive interactions, while in others, the importance of the critical interactions was only elucidated in subsequent computational and mechanistic studies. Through an exploration and discussion of recent reports encompassing a wide range of reaction classes, we hope to inspire synthetic chemists to continue to develop asymmetric transformations based on this powerful concept.The EPSRC are acknowledged in manuscript as they provide a studentship to one of the authors

    Catalytic Asymmetric Synthesis of Butenolides and Butyrolactones

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    γ-Butenolides, γ-butyrolactones, and derivatives, especially in enantiomerically pure form, constitute the structural core of numerous natural products which display an impressive range of biological activities which are important for the development of novel physiological and therapeutic agents. Furthermore, optically active γ-butenolides and γ-butyrolactones serve also as a prominent class of chiral building blocks for the synthesis of diverse biological active compounds and complex molecules. Taking into account the varying biological activity profiles and wide-ranging structural diversity of the optically active γ-butenolide or γ-butyrolactone structure, the development of asymmetric synthetic strategies for assembling such challenging scaffolds has attracted major attention from synthetic chemists in the past decade. This review offers an overview of the different enantioselective synthesis of γ-butenolides and γ-butyrolactones which employ catalytic amounts of metal complexes or organocatalysts, with emphasis focused on the mechanistic issues that account for the observed stereocontrol of the representative reactions, as well as practical applications and synthetic potentialsWe gratefully acknowledge generous support from The Netherlands Organization for Scientific Research (NWO-CW, Top grant to B.L.F.), the Royal Netherlands Academy of Arts and Sciences (KNAW), the Ministry of Education, Culture and Science (Gravitation Programme 024.001.035), the European Research Council (Advanced Investigator Grant 694345 to B.L.F.), and the Spanish Ministry of Economy and Competitiveness (Ramón y Cajal contract to M.F.-M.). B.M. gratefully thanks the Chinese National Natural Science Foundation (21606200) and the start-up fund from Zhejiang University of Technology for financial supportS
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