Unstable vortices do not confine

Recently, a geometric model for the confinement of magnetic charges in the context of type II string compactifications was constructed by Greene, Morrison and Vafa. This model assumes the existence of stable magnetic vortices with quantized flux in the low energy theory. However, quantization of flux alone does not imply that the vortex is stable, since the flux may not be confined to a tube of definite size. We show that in the field theoretical model which underlies the geometric model of confinement, static, cylindrically symmetric magnetic vortices do not exist. While our results do not preclude the existence of confinement in a different low-energy regime of string theory, they show that confinement is not a universal outcome of the string picture, and its origin in the low energy theory remains to be understood.Comment: Latex, 8 page

Supersymmetric non-abelian Born-Infeld revisited

We determine the non-abelian Born-Infeld action, including fermions, as it results from the four-point tree-level open superstring scattering amplitudes at order alpha'^2. We find that, after an appropriate field redefinition all terms at this order can be written as a symmetrised trace. We confront this action with the results that follow from kappa-symmetry and conclude that the recently proposed non-abelian kappa-symmetry cannot be extended to cubic orders in the Born-Infeld curvature.Comment: 26 pages, Late

A Case for Reverse Incorporation of Academic Legal Scholarship into Conflict Management Studies

The article takes as its point of departure some of the author’s multidisciplinary projects. Special attention is given to the question of whether the disciplines united in the vari- ous research team members already constituted a kind of ‘inter-discipline’, through which a single object was studied. The issue of how the disciplinary orientations of the research team members occasionally clashed, on methodological issues, is also addressed. The outcomes of these and similar multidisciplinary research projects are followed back into legal practice and academic legal scholarship to uncover whether an incorporation prob- lem indeed exists. Here, special attention will be given to policy recommendations and notably proposals for new leg- islation. After all, according to Van Dijck et al., the typical role model for legal researchers working from an internal perspective on the law is the legislator. The author concludes by making a somewhat bold case for reverse incorporation, that is, the need for (traditional) aca- demic legal research to become an integral part of a more encompassing (inter-)discipline, referred to here as ‘conflict management studies’. Key factors that will contribute to the rise of such a broad (inter-)discipline are the changes that currently permeate legal practice (the target audience of tra- ditional legal research) and the changes in the overall financing of academic research itself (with special reference to the Netherlands)

Emergence timing and morphological characteristics of Galium populations in western Canada

Non-Peer Reviewe

Molecular discrimination of catchweed bedstraw (Galium aparine L.) and false cleavers (Galium spurium L.) in western Canada

Non-Peer Reviewe

Towards a Pan-European Integrated Groundwater and Surface Water Model: Development and Applications

During the last years, we have developed a model, which is able to simulate hydrological processes at a Pan-European scale. The model has multiple possible uses, including flood forecasting, identification of groundwater recharge / discharge zones and large-scale water resources management. The integrated model is based on the LISFLOOD model, which simulates hydrological processes with a focus on snow and soil hydrology and streamflow routing. The area of interest is the full European continent, divided in 5 × 5 km cells. A conceptual 2D MODFLOW model was linked to improve groundwater simulation. With this coupling, it is now possible to simulate the water exchanges between adjacent cells, and between groundwater and river. Available meteorological data from 1-1-1990 to 31-10-2014 were used as input for the coupled model, together with values of aquifer properties derived from literature. We used observed data of recharge, discharge and hydraulic heads from the Danube river basin to check if the model results correspond to reality. The results show a reasonably high degree of agreement between observed and simulated data, taking into account the limitations of large scale modelling. This model is the first step to improve integrated groundwater and surface water modelling which includes the collection of data and the production of Pan-European groundwater parameter maps

alpha'-Corrections to Heterotic Superstring Effective Action Revisited

In this letter we establish that the supersymmetric R^2 effective action for the heterotic string, obtained from the supersymmetrisation of the Lorentz Chern-Simons term, is to order $\alpha'$ equivalent modulo field redefinitions to heterotic string effective actions computed by different methods.Comment: 7 page

Scaling Cosmologies of N=8 Gauged Supergravity

We construct exact cosmological scaling solutions in N=8 gauged supergravity. We restrict to solutions for which the scalar fields trace out geodesic curves on the scalar manifold. Under these restrictions it is shown that the axionic scalars are necessarily constant. The potential is then a sum of exponentials and has a very specific form that allows for scaling solutions. The scaling solutions describe eternal accelerating and decelerating power-law universes, which are all unstable. An uplift of the solutions to 11-dimensional supergravity is carried out and the resulting timedependent geometries are discussed. In the discussion we briefly comment on the fact that N=2 gauged supergravity allows stable scaling solutions.Comment: 17 pages; referenced added, reportnr changed and some corrections in section