Union Membership Statistics in 24 Countries

[From p. 38] An analysis of adjusted union membership data in 24 countries yields past and present union density rates; the data provide explanatory factors for the differences and trends in unionization

Holographic Reconstruction of 3D Flat Space-Time

We study asymptotically flat space-times in 3 dimensions for Einstein gravity near future null infinity and show that the boundary is described by Carrollian geometry. This is used to add sources to the BMS gauge corresponding to a non-trivial boundary metric in the sense of Carrollian geometry. We then solve the Einstein equations in a derivative expansion and derive a general set of equations that take the form of Ward identities. Next, it is shown that there is a well-posed variational problem at future null infinity without the need to add any boundary term. By varying the on-shell action with respect to the metric data of the boundary Carrollian geometry we are able to define a boundary energy-momentum tensor at future null infinity. We show that its diffeomorphism Ward identity is compatible with Einstein's equations. There is another Ward identity that states that the energy flux vanishes. It is this fact that is responsible for the enhancement of global symmetries to the full BMS$_3$ algebra when we are dealing with constant boundary sources. Using a notion of generalized conformal boundary Killing vector we can construct all conserved BMS$_3$ currents from the boundary energy-momentum tensor.Comment: v3: clarifications added, matches published versio

An organisational perspective on social exclusion in higher education : a case study

We explore organisational mechanisms underlying social exclusion in higher education, the latter defined as the underrepresentation of students from lower socio-economic backgrounds. We focus on “decoupling,†which is a central concept in organisational institutionalism referring to the construction of gaps between public commitment and core organisational practices, a common phenomenon in organisations worldwide. In the context of social inclusion this implies that universities are often publicly committed to social inclusion whereas their actual practices reproduce social exclusion. Drawing on an in-depth case study of a Flemish university, we identify four possible antecedents of decoupling: institutional contradictions resulting from the neo-liberalisation of higher education, uncertainty about effective inclusive practices, resistance of key constituencies and resource stringency resulting from experiences of lacking public funding

Gauging the Carroll Algebra and Ultra-Relativistic Gravity

It is well known that the geometrical framework of Riemannian geometry that underlies general relativity and its torsionful extension to Riemann-Cartan geometry can be obtained from a procedure known as gauging the Poincare algebra. Recently it has been shown that gauging the centrally extended Galilei algebra, known as the Bargmann algebra, leads to a geometrical framework that when made dynamical gives rise to Horava-Lifshitz gravity. Here we consider the case where we contract the Poincare algebra by sending the speed of light to zero leading to the Carroll algebra. We show how this algebra can be gauged and we construct the most general affine connection leading to the geometry of so-called Carrollian space-times. Carrollian space-times appear for example as the geometry on null hypersurfaces in a Lorentzian space-time of one dimension higher. We also construct theories of ultra-relativistic (Carrollian) gravity in 2+1 dimensions with dynamical exponent z<1 including cases that have anisotropic Weyl invariance for z=0.Comment: 27 page

A targeted public: public services in fifteenth-century Ghent and Bruges

Though the phrase 'public services' is a nineteenth-century invention, which was supported by a developed rhetoric of political economy, this article shows that the concept, practice and supply of such services could also be found in the medieval city. It specifically analyses three areas of urban service provision: jurisprudence and legal security, infrastructure and finally health care and poor relief. Although the available sources tend to stress the involvement of municipal authorities in providing public services, it turns out that in fact the furnishing of services was highly multi-layered. In all three areas studied, a wide range of public and private institutions offered services to specific groups within late medieval urban society. In contrast to what the notion of 'public services' lets us presume, however, public services in the medieval city were not available to all inhabitants. Instead, the provision of services was usually quite restrictive, and targeted particular groups in society