Isospectral Alexandrov Spaces

We construct the first non-trivial examples of compact non-isometric Alexandrov spaces which are isospectral with respect to the Laplacian and not isometric to Riemannian orbifolds. This construction generalizes independent earlier results by the authors based on Schueth's version of the torus method.Comment: 15 pages, no figures; minor clarification

Suborbifolds and groupoid embeddings

Given the notion of suborbifold of the second author (based on ideas of Borzellino/Brunsden) and the classical correspondence (up to certain equivalences) between (effective) orbifolds via atlases and effective orbifold groupoids, we analyze which groupoid embeddings correspond to suborbifolds and give classes of suborbifolds naturally leading to groupoid embeddings.Comment: 14 pages; numbering adjusted to journal publication, new Example 3 in Section

Discretization strategies for computing Conley indices and Morse decompositions of flows

Conley indices and Morse decompositions of flows can be found by using algorithms which rigorously analyze discrete dynamical systems. This usually involves integrating a time discretization of the flow using interval arithmetic. We compare the old idea of fixing a time step as a parameters to a time step continuously varying in phase space. We present an example where this second strategy necessarily yields better numerical outputs and prove that our outputs yield a valid Morse decomposition of the given flow

SPD members should think twice before vetoing Germany's grand coalition

The results of the German Social Democrats' (SPD) membership referendum on Germany's new grand coalition are expected on 4 March. Ragnar Weilandt argues that opponents of the grand coalition should think twice before vetoing it. SPD members fear that four more years under chancellor Merkel might destroy their party. But the alternatives may be worse for Germany, Europe and the SPD itself

Socio-economic challenges to Tunisia’s democratic transition

Among those countries that faced the so-called Arab Spring in 2011, Tunisia is the last one for which hope for a successful democratic transition remains justified. However, the country’s comparatively favourable institutional evolution has led to a dangerous complacency not only in Europe but across the West. While important reforms have been implemented, democracy has so far failed to fulfil the high expectations it has raised within the population. Tunisians’ discontent with their living conditions and the new system’s perceived inability to deliver are fundamental threats to the country’s transition. This article argues that the EU has a major interest in making Tunisia a democratic and socio-economic success story, as failure would not only constitute a lost opportunity to create a role model in the region but would also jeopardise European security interests. The EU should therefore provide more substantial support with the aim of realising socio-economic improvements in Tunisia

Divisions within post-2011 Tunisia’s secular civil society

Popular and academic discourses frame civil society as a key factor that prevented Tunisia from following the unfortunate path of other “Arab Spring” states. But while such discourses tend to portray it as a monolithic political force, Tunisian civil society comprises a diverse range of different types of actors with different backgrounds, interests, views and approaches towards activism. Drawing upon interviews with Tunisian activists, this article maps a range of tensions within Tunisian secular civil society along these lines and sets out to explain their origins. Notably, it identifies a generational division between those activists that started to engage in the late 2000s or during and after the 2011 ouster of Ben Ali and those who were already active before. This division is based on a range of factors, including a sense of entitlement to the leadership of post-2011 Tunisian civil society on both sides, a lack of mutual respect for and trust in each other as well as differences regarding practices and priorities of civil society engagement