Covariogram of non-convex sets

The covariogram of a compact set A contained in R^n is the function that to each x in R^n associates the volume of A intersected with (A+x). Recently it has been proved that the covariogram determines any planar convex body, in the class of all convex bodies. We extend the class of sets in which a planar convex body is determined by its covariogram. Moreover, we prove that there is no pair of non-congruent planar polyominoes consisting of less than 9 points that have equal discrete covariogram.Comment: 15 pages, 7 figures, accepted for publication on Mathematik

Spatial Cournot Competition and Consumers’ Heterogeneity: A Note

We consider the standard model of spatial Cournot competition and show that a necessary condition for dispersion equilibria is that the distribution be not unimodal.Spatial Cournot competition, consumers’ distribution

Does regional development explain international youth mobility? Spatial patterns and global/local determinants of the recent emigration of young Italians

In this essay, we tackle the issue of the international mobility of young Italians in relation to regional disparities. Our intention is to determine if and to what extent a relationship exists between regional development and the international mobility of young people. We analyze the international migration of Italian citizens aged 15-34 who left the country in the period 2010-2017 using several variables that reflect the varying conditions found in different NUTS 3-level regions in terms of economic dynamism, labor-market efficiency, social fragility, educational underdevelopment and spatial peripherality. Ordinary Least Squares (OLS) and Geographically Weighted Regression (GWR) models show that the international mobility of young Italians is very much dependent on local conditions and affected by spatial differences. It is greatest in the most economically dynamic areas of the country, in border regions and in metropolitan areas, with factors relating to spatial proximity and peripherality, imbalances in local labor markets, and paucity of human capital proving particularly significant

Nonparametric estimation of the local Hurst function of multifractional Gaussian processes

A new nonparametric estimator of the local Hurst function of a multifractional Gaussian process based on the increment ratio (IR) statistic is defined. In a general frame, the point-wise and uniform weak and strong consistency and a multidimensional central limit theorem for this estimator are established. Similar results are obtained for a refinement of the generalized quadratic variations (QV) estimator. The example of the multifractional Brownian motion is studied in detail. A simulation study is included showing that the IR-estimator is more accurate than the QV-estimator

Role of surface states in the Casimir force between semiconducting films

We present results of first principle calculations of the Casimir force between Si films of nanometric size, which show that it depends significantly upon the configuration of the surface atoms, and give evidence of the importance of surface states.Comment: to be published on J.Phys.

Correlation inequalities for the quantum XY model

We show the positivity or negativity of truncated correlation functions in the quantum XY model with spin 1/2 (at any temperature) and spin 1 (in the ground state). These Griffiths-Ginibre inequalities of the second kind generalise an earlier result of Gallavotti.Comment: 9 page

Alternative routes to good jobs in the service economy: Employment restructuring and human resource management in incumbent telecommunications firms

This is a practitioner report detailing findings from a three-year study on organizational restructuring and employment outcomes at 10 incumbent telecommunications firms, supported by the Economic and Social Research Council. It presents background on markets, ownership, and institutions in the case study firms and countries, and compares restructuring policies in three areas: downsizing and employment adjustment; diversifying employment contracts; and work organization and human resource Management. The report concludes with policy recommendations, based on findings from the study.ESRC Grant RES-061-25-044

Institutions and Inequality in Liberalizing Markets: Explaining Different Trajectories of Institutional Change in Social Europe

Economic and Social Research Council [grant number RES-061-25-0444]