Transnational issue agendas of the radical right? Parties’ Facebook campaign communication in six countries during the 2019 European Parliament election

In this study, we investigate to what degree radical right parties use social media for pushing a common issue agenda to mobilise voters on a pan-European scale. Using the 2019 European Parliament (EP) election as a case, we analysed radical right parties’ campaign agendas in Austria, France, Germany, Italy, Poland and Sweden and identified the transnationally shared issue repertoire in their Facebook communication. Based on the structural topic modelling we used for analysis, our results reveal a set of shared issues – immigration and blaming elites –which are typical of the populist core of those parties. Moreover, all parties use social media to draw attention to the election itself. While radical right parties mobilise their voters based on a transnationally recurring set of shared issues, national political opportunity structures account for party-specific topics and national adaptations of shared issues in their campaigns on Facebook

Implications of Hyperon Pairing for Cooling of Neutron Stars

The implications of hyperon pairing for the thermal evolution of neutron stars containing hyperons are investigated. The outcome of cooling simulations are compared for neutron star models composed only of nucleons and leptons, models including hyperons, and models including pairing of hyperons. We show that lambda and neutron pairing suppresses all possible fast neutrino emission processes in not too massive neutron stars. The inclusion of lambda pairing yields better agreement with X-ray observations of pulsars. Particularly, the surface temperatures deduced from X-ray observations within the hydrogen atmosphere model are more consistent with the thermal history of neutron stars containing hyperons, if the critical temperature for the onset of lambda and nucleon pairing is not too small.Comment: 7 pages, 3 figures. To be published in ApJL. The postscript and additional tables can be found at http://www.physik.uni-muenchen.de/sektion/suessmann/astro/cool/schaab.089

Neutrino Emission from Cooper Pairs and Minimal Cooling of Neutron Stars

The minimal cooling paradigm for neutron star cooling assumes that enhanced cooling due to neutrino emission from any direct Urca process, due either to nucleons or to exotica such as hyperons, Bose condensates, or deconfined quarks, does not occur. This scenario was developed to replace and extend the so-called standard cooling scenario to include neutrino emission from the Cooper pair breaking and formation processes that occur near the critical temperature for superfluid/superconductor pairing. Recently, it has been found that Cooper-pair neutrino emission from the vector channel is suppressed by a large factor compared to the original estimates that violated vector current conservation. We show that Cooper-pair neutrino emission remains, nevertheless, an efficient cooling mechanism through the axial channel. As a result, the elimination of neutrino emission from Cooper-paired nucleons through the vector channel has only minor effects on the long-term cooling of neutron stars within the minimal cooling paradigm. We further quantify precisely the effect of the size of the neutron 3P2 gap and demonstrate that consistency between observations and the minimal cooling paradigm requires that the critical temperature T_c for this gap covers a range of values between T_c^min 0.5 \times 10^9 K in the core of the star. In addition, it is required that young neutron stars have heterogenous envelope compositions: some must have light-element compositions and others must have heavy-element compositions. Unless these two conditions are fulfilled, about half of the observed young cooling neutron stars are inconsistent with the minimal cooling paradigm and provide evidence for the existence of enhanced cooling.Comment: 13 pages, 9 figures, submitted to Ap

Roton-phonon excitations in Chern-Simons matter theory at finite density

We consider SU(N) Chern-Simons theory coupled to a scalar field in the fun- damental representation at strictly zero temperature and finite chemical potential for the global U(1)B particle number or flavour symmetry. In the semiclassical regime we identify a Bose condensed ground state with a vacuum expectation value (VEV) for the scalar accom- panied by noncommuting background gauge field matrix VEVs. These matrices coincide with the droplet ground state of the Abelian quantum Hall matrix model. The ground state spontaneously breaks U(1)B and Higgses the gauge group whilst preserving spatial rotations and a colour-flavour locked global U(1) symmetry. We compute the perturbative spectrum of semiclassical fluctuations for the SU(2) theory and show the existence of a single massless state with a linear phonon dispersion relation and a roton minimum (and maximum) determining the Landau critical superfluid velocity. For the massless scalar theory with vanishing self interactions, the semiclassical dispersion relations and location of roton extrema take on universal forms