Multicritical behavior in models with two competing order parameters

We employ the nonperturbative functional Renormalization Group to study models with an O(N_1)+O(N_2) symmetry. Here, different fixed points exist in three dimensions, corresponding to bicritical and tetracritical behavior induced by the competition of two order parameters. We discuss the critical behavior of the symmetry-enhanced isotropic, the decoupled and the biconical fixed point, and analyze their stability in the N_1, N_2 plane. We study the fate of non-trivial fixed points during the transition from three to four dimensions, finding evidence for a triviality problem for coupled two-scalar models in high-energy physics. We also point out the possibility of non-canonical critical exponents at semi-Gaussian fixed points and show the emergence of Goldstone modes from discrete symmetries.Comment: 16 pages, 7 figures, 5 tables, minor changes in updated version, identical to published one in Phys. Rev.

Discovering and quantifying nontrivial fixed points in multi-field models

We use the functional renormalization group and the $\epsilon$-expansion concertedly to explore multicritical universality classes for coupled $\bigoplus_i O(N_i)$ vector-field models in three Euclidean dimensions. Exploiting the complementary strengths of these two methods we show how to make progress in theories with large numbers of interactions, and a large number of possible symmetry-breaking patterns. For the three- and four-field models we find a new fixed point that arises from the mutual interaction between different field sectors, and we establish the absence of infrared-stable fixed point solutions for the regime of small $N_i$. Moreover, we explore these systems as toy models for theories that are both asymptotically safe and infrared complete. In particular, we show that these models exhibit complete renormalization group trajectories that begin and end at nontrivial fixed points.Comment: 10 pages, 6 figures; minor changes, as published in EPJ

The Carvedilol Prospective Randomized Cumulative Survival (COPERNICUS) trial

Previous trials (Metoprolol CR/XL Randomised Intervention Trial in Congestive Heart Failure [MERIT-HF], Cardiac Insufficiency Bisoprolol Study [CIBIS] II) have demonstrated a mortality benefit of β-adrenergic blockade in patients with mild to moderate heart failure. The recent Carvedilol Prospective Randomized Cumulative Survival (COPERNICUS) trial has extended these results to a more advanced patient population. This trial did not, however, include patients who could not reach compensation, patients with far advanced heart failure symptoms, or a significant number of black patients. Future studies of β-blockade may focus on these patients or patients with asymptomatic left ventricular dysfunction

Fit für die digitale Hochschule?

Die digitale Transformation stellt Hochschullehrende zunehmend vor die Herausforderung, eigene digitale Kompetenzen aufzubauen und zu stärken, um im Rahmen ihrer Profession aktuellen Erfordernissen gerecht zu werden. Der vorliegende Beitrag beschreibt die Entwicklung eines Kompetenzmodells, mit dem sich digitale Kompetenzen von Hochschullehrenden auf acht Dimensionen und drei Kompetenzstufen erfassen lassen. Weiterhin werden ein auf dem Modell basierendes Kompetenzraster sowie ein Instrument zur Selbsteinschätzung digitaler Kompetenzen beschrieben und erste Validierungsergebnisse vorgestellt. Der Beitrag gibt abschliessend einen Ausblick auf Anwendungsmöglichkeiten des Kompetenzrasters für Lehrpersonen sowie für Mitarbeitende in der hochschuldidaktischen Qualifizierung und Beratung