Microscopic Theory for Long Range Spatial Correlations in Lattice Gas Automata

Lattice gas automata with collision rules that violate the conditions of semi-detailed-balance exhibit algebraic decay of equal time spatial correlations between fluctuations of conserved densities. This is shown on the basis of a systematic microscopic theory. Analytical expressions for the dominant long range behavior of correlation functions are derived using kinetic theory. We discuss a model of interacting random walkers with x-y anisotropy whose pair correlation function decays as 1/r^2, and an isotropic fluid-type model with momentum correlations decaying as 1/r^2. The pair correlation function for an interacting random walker model with interactions satisfying all symmetries of the square lattice is shown to have 1/r^4 density correlations. Theoretical predictions for the amplitude of the algebraic tails are compared with the results of computer simulations.Comment: 31 pages, 2 figures, final version as publishe

Rationales of Care in Contemporary Welfare States: The Case of Childcare in the Netherlands

Past research project

Recent Changes in European Welfare State Services: A Comparison of Child Care Politics in the U.K., Sweden, Germany, and the Netherlands. CES Germany & Europe Working Papers, No. 07.6, 1997

This paper examines recent policies and politics of services, in particular child care services in European welfare states. It is argued that social (care) services are becoming an increasingly political issue in postindustrial societies and are at the very center of welfare-state restructuring. Some countries have recently developed new policy pro­ grams for child care-but there are important differences among these programs. To understand these differences as well as some common features, the paper argues that it is necessary to examine the institutional organization of child care and short-term political factors as well as the rationales articulated in political debates to support or im­ pede various policies. The paper concludes that a comprehensive system of child care provisions is still far off in most countries, despite a rhetoric of choice and postindustrial care and labor-market patterns

A (49,16,3,6) strongly regular graph does not exist

Graphs;mathematics

On (v,k,labda) graphs and designs with trivial automorphism group

Mathematics