We describe situations in which chains of N degenerate quantum energy levels, coupled by time-dependent external fields, can be replaced by independent sets of chains of length N, N−1, . . . ,2 and sets of uncoupled single states. The transformation is a generalization of the two-level Morris-Shore transformation J.R. Morris and B.W. Shore, Phys. Rev. A 27, 906 1983 . We illustrate the procedur...

This text explores locally recruited staff within a growing category of organisations in the international aid industry: Development Finance Institutions (DFIs). DFIs are banks that offer risk capital to development projects global South, increasingly using tax-funded money. Based on interviews with 13 DFI investment managers, I show how Kenyan challenge three signature attributes commonly assi...

We argue that the planar optical waveguide is the geometry of choice for observing electromagnetic Stark ladders.

Transmission and reflectivity of La x Ca 14−x Cu 24 O 41 two-leg spin-1/2 ladders were measured in the mid-infrared regime between 500 and 12 000 cm −1. This allows us to determine the optical conductivity σ 1 directly and with high sensitivity. Here we show data for x=4 and 5 with the electrical field polarized parallel to the rungs (E || a) and to the legs (E || c). Three characteristic peaks...

In this paper, we examine the mechanisms underlying the perceptual integration of two types of contour: snakes (composed of Gabor elements parallel to the path of the contour) and ladders (with elements perpendicular to the path). We varied the element separation and carrier wavelength. Increasing the element separation impaired detection of snakes but did not affect ladders; at high separation...

D. J. Field, A. Hayes, and R. F. Hess (1993) introduced two types of stimulus to study the perceptual integration of contours. Both types of stimulus consist of a smooth path of spatially separate elements, embedded in a field of randomly oriented elements. In one type of stimulus ("snakes"), the elements form tangents to the path of the contour; in the other type ("ladders"), the elements are ...

In this paper we present suucient conditions for unweighted digraphs to induce facet-deening inequalities of the linear ordering polytope P n. We introduce constructive operations (Identiication (of nodes),5-Extension) for generating new facets of P n by using already known facets. The identiication generates new digraphs by identiication two nodes of the source di-graph and presented for arbit...

We introduce a new class of valid inequalities for the symmetric travelling salesman polytope. The family is not of the common handle-tooth variety. We show that these inequalities are all facet-inducing and have Chvv atal rank 2.