Commensurability effects for fermionic atoms trapped in 1D optical lattices

Fermionic atoms in two different hyperfine states confined in optical lattices show strong commensurability effects due to the interplay between the atomic density wave (ADW) ordering and the lattice potential. We show that spatially separated regions of commensurable and incommensurable phases can coexist. The commensurability between the harmonic trap and the lattice sites can be used to control the amplitude of the atomic density waves in the central region of the trap.Comment: Accepted for publication in Physical Review Letter

Poder real absoluto. Oligarquías y transformaciones del paisaje agrario en el Marquesado de Villena a finales de la Edad Media

Los estudios realizados sobre la apropiación de tierras comunales en Castilla han puesto gran parte de su énfasis en motivos demográfi cos o en la crisis del siglo XIV. No obstante, pensamos que el gran auge de dicho fenómeno experimentado a fi nales del siglo XV y principios del XVI debe mucho al desarrollo del poder de la monarquía y la defi nición de su modelo de organización social, que establece la necesidad de reconocer el papel de las oligarquías en el mundo urbano como elemento necesario para la implantación de la autoridad regia en las ciudades. La necesidad de la Corona de contar con dichas oligarquías facultaría a estas a desarrollar una campaña agresiva tendente a aumentar sus patrimonios, base de su reproducción y perpetuación social.Studies carried out on the illegal occupation of common land in Castile have put that occupation down to demographic factors or to the crisis of the 14th century. However, I believe that the huge increase in the illegal occupation of land at the end of the 15th century and beginning of the 16th century was largely due to the increase of the power of the king and to his model of social organisation. The king believed in the need to recognise the importance of the oligarchies if he wanted to enforce his own authority in the towns and cities. The oligarchies took advantage of this dependence of the crown on them to increase their wealth and possessions and perpetuate their social position

Virtualisation of the test environment for signalling

ERTMS is a well-known, well-performing technology applied all over the world but it still lacks flexibility when it comes to authorisation and certification procedures. The key of its success in the future lies as much in cost reduction as in simplification of placing in service procedures. This holds true for the implementation of a new subsystem and even more so for new software releases related to subsystems already in service. Currently the placing in service process of ETCS components and subsystems requires a large amount of tests due to the complexity of the signalling systems and the different engineering rules applied. The S2R Multi-Annual Action Plan states that the effort and time consumption of these onsite tests are at least 30% for any particular project. VITE research project (VIrtualisation of the Test Environment) aims at reducing these onsite tests to a minimum while ensuring that laboratory tests can serve as evidence for valid system behaviour and are accepted by all stakeholders involved in the placing in service process. This paper presents the first VITE results