Book review: exceptional people: how migration shaped our world and will define our future

Arnaud Vaganay finds Ian Goldin’s recent book to be a great contribution to migration studies, packed with statistics, maps, and important discussions on migratory pressure in Europe

Combinatorial cohomology of the space of long knots

The motivation of this work is to define cohomology classes in the space of knots that are both easy to find and to evaluate, by reducing the problem to simple linear algebra. We achieve this goal by defining a combinatorial graded cochain complex, such that the elements of an explicit submodule in the cohomology define algebraic intersections with some "geometrically simple" strata in the space of knots. Such strata are endowed with explicit co-orientations, that are canonical in some sense. The combinatorial tools involved are natural generalisations (degeneracies) of usual methods using arrow diagrams.Comment: 20p. 9 fig

Cluster algorithm for non-additive hard-core mixtures

In this paper, we present a cluster algorithm for the numerical simulations of non-additive hard-core mixtures. This algorithm allows one to simulate and equilibrate systems with a number of particles two orders of magnitude larger than previous simulations. The phase separation for symmetric binary mixtures is studied for different non-additvities as well as for the Widom-Rowlinson model (B. Widom and J. S. Rowlinson, J. Chem. Phys. 52, 1670 (1970)) in two and three dimensions. The critical densities are determined from finite size scaling. The critical exponents for all the non-additivities are consistent with the Ising universality class.Comment: 11 pages and 9 figures, to be published in J. Chem. Phys. Minor corrections and some references adde

Classification of polynomials from C^2 to C with one critical value

We give the classification, up to homeomorphisms, of reduced complex polynomials with 2 variables with one critical value.Comment: 17 pages, LaTeX2e, 2 figures, 2 tabulars. To appear in Mathematische Zeitscrift. One remark changed after theorem