Search results for " Quotients"

showing 5 items of 5 documents

A closer look at mirrors and quotients of Calabi-Yau threefolds

2016

Let X be the toric variety (P1)4 associated with its four-dimensional polytope 1. Denote by X˜ the resolution of the singular Fano variety Xo associated with the dual polytope 1o. Generically, anticanonical sections Y of X and anticanonical sections Y˜ of X˜ are mirror partners in the sense of Batyrev. Our main result is the following: the Hodge-theoretic mirror of the quotient Z associated to a maximal admissible pair (Y, G) in X is not a quotient Z˜ associated to an admissible pair in X˜ . Nevertheless, it is possible to construct a mirror orbifold for Z by means of a quotient of a suitable Y˜. Its crepant resolution is a Calabi-Yau threefold with Hodge numbers (8, 4). Instead, if we star…

Pure mathematics010308 nuclear & particles physics010102 general mathematicsToric varietyPolytopeFano varietymirror symmetry01 natural sciencesTheoretical Computer ScienceMathematics::Algebraic GeometryMathematics (miscellaneous)0103 physical sciencesCalabi-YauCrepant resolutionCalabi–Yau manifoldMirror Symmetry Calabi-Yau QuotientsSettore MAT/03 - Geometria0101 mathematicsMathematics::Symplectic GeometryQuotientOrbifoldMAT/03 - GEOMETRIAMathematicsResolution (algebra)
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Witt vectors and Fermat quotients

2008

Abstract We give a representation of any integer as a vector of the Witt ring W ( Z p ) and relate it to the Fermat quotient q ( n ) = ( n p − 1 − 1 ) / p . Logarithms are introduced in order to establish an isomorphism between the commutative unipotent groups 1 + p W ( Z p ) and W ( Z p ) .

Witt vectors Fermat QuotientsFermat quotientRing (mathematics)Pure mathematicsAlgebra and Number TheoryIntegerOrder (ring theory)IsomorphismUnipotentWitt vectorQuotientMathematicsJournal of Number Theory
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Residential segregation of foreigners: an analysis of the Italian city of Palermo

2015

Ethnic residential segregation in Italy is an emerging key question, which will be crucial in the definition and implementation of both urbanistic and social policies. This paper focuses on this phenomenon in the Italian city of Palermo. We use individual data for all the population residing in the city at 31 December 2011, organized by ethnicity and district. Firstly, we describe the spatial distribution and the residential segregation of foreigners in the city, applying many different segregation measures. Among the others, we also apply the Duncan and Duncan dissimilarity index. Finally, we apply a recent methodological approach, which allows reducing the bias of the Duncan’s index…

residential segregation; segregation indices; location quotients; Duncan's dissimilarity index; bias correctionlocation quotientresidential segregation ; bias correction; segregation indices location quotients Duncan’s dissimilarity indexresidential segregationDuncan’s dissimilarity indexsegregation indicesegregation indicesSettore SECS-S/04 - Demografiabias correctionlocation quotients
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Estimating Regional Input Coefficients and Multipliers: The Use of FLQ is Not a Gamble

2014

Flegg A. T. and Tohmo T. Estimating regional input coefficients and multipliers: the use of FLQ is not a gamble, Regional Studies. This paper re-examines the Finnish evidence presented by Lehtonen and Tykkylainen on the use of location quotients (LQs) in estimating regional input coefficients and multipliers. They argue that the choice of an LQ-based method is a gamble and that there is no single method that can be recommended for general use. It is contended here that this evidence is erroneous and that the FLQ (Flegg's location quotient) yields results far superior to those from competing formulae, so it should provide a satisfactory way of generating an initial set of input coefficients.…

ta51105 social sciences0211 other engineering and technologiesGeneral Social Sciences021107 urban & regional planning02 engineering and technologylocation quotientsSet (abstract data type)FLQ formulaRegional studies0502 economics and businessStatisticsmultipliersEconomic base analysista519050207 economicsValue (mathematics)QuotientFinlandregional input–output tablesGeneral Environmental ScienceMathematicsRegional Studies
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The regionalization of national input-output tables : A study of South Korean regions

2018

This paper uses survey‐based data for 16 South Korean regions to refine the application of Flegg's location quotient (FLQ) and its variant, the sector‐specific FLQ (SFLQ). These regions vary markedly in terms of size. Especial attention is paid to the problem of choosing appropriate values for the unknown parameter δ in these formulae. Alternative approaches to this problem are evaluated and tested. Our paper adds to earlier research that aims to find a cost‐effective way of adapting national coefficients, so as to produce a satisfactory initial set of regional input coefficients for regions where survey‐based data are unavailable. Este documento utiliza datos basados en encuestas de 16 reg…

ta511input-outputWelfare economics05 social sciencesGeography Planning and DevelopmentFLQ0211 other engineering and technologies021107 urban & regional planning02 engineering and technologyEnvironmental Science (miscellaneous)location quotientsEtelä-KoreaSouth Korea0502 economics and businessSFLQta519aluetalous050207 economicspanos-tuotosanalyysiMathematicsPapers in Regional Science
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