Heterogeneous migration flows from the Central Plateau of Burkina Faso: the role of natural and social capital

This paper uses a system of labour supply equations and data from Burkina Faso collected in 2003 to test the conditions underlying two different migratory movements: continental and intercontinental migration. We provide theoretical reasoning and empirical evidence that heterogeneity in migration is related to heterogeneity in rural households. We find that comparatively asset-poor households embark on continental migration, whereas intercontinental migration takes place in comparatively wealthy households in response to opportunities for accumulation of wealth in Europe. We also find that access to religion-specific migrant networks plays a positive and negative role in explaining, respectively, intercontinental and continental migratio

Extinctions and Correlations for Uniformly Discrete Point Processes with Pure Point Dynamical Spectra

The paper investigates how correlations can completely specify a uniformly discrete point process. The setting is that of uniformly discrete point sets in real space for which the corresponding dynamical hull is ergodic. The first result is that all of the essential physical information in such a system is derivable from its $n$-point correlations, $n= 2, 3, >...$. If the system is pure point diffractive an upper bound on the number of correlations required can be derived from the cycle structure of a graph formed from the dynamical and Bragg spectra. In particular, if the diffraction has no extinctions, then the 2 and 3 point correlations contain all the relevant information.Comment: 16 page

Probing the energy bands of a Bose-Einstein condensate in an optical lattice

We simulate three experimental methods which could be realized in the laboratory to probe the band excitation energies and the momentum distribution of a Bose-Einstein condensate inside an optical lattice. The values of the excitation energies obtained in these different methods agree within the accuracy of the simulation. The meaning of the results in terms of density and phase deformations is tested by studying the relaxation of a phase-modulated condensate towards the ground state.Comment: 5 pages, 5 figure