Emerging Internal Symmetries from Effective Spacetimes

Can global internal and spacetime symmetries be connected without supersymmetry? To answer this question, we investigate Minkowski spacetimes with d space-like extra dimensions and point out under which general conditions external symmetries induce internal symmetries in the effective 4-dimensional theories. We further discuss in this context how internal degrees of freedom and spacetime symmetries can mix without supersymmetry in agreement with the Coleman-Mandula theorem. We present some specific examples which rely on a direct product structure of spacetime such that orthogonal extra dimensions can have symmetries which mix with global internal symmetries. This mechanism opens up new opportunities to understand global symmetries in particle physics

Gravitational Waves as a New Probe of Bose-Einstein Condensate Dark Matter

There exists a class of ultralight Dark Matter (DM) models which could form a Bose-Einstein condensate (BEC) in the early universe and behave as a single coherent wave instead of individual particles in galaxies. We show that a generic BEC DM halo intervening along the line of sight of a gravitational wave (GW) signal could induce an observable change in the speed of GW, with the effective refractive index depending only on the mass and self-interaction of the constituent DM particles and the GW frequency. Hence, we propose to use the deviation in the speed of GW as a new probe of the BEC DM parameter space. With a multi-messenger approach to GW astronomy and/or with extended sensitivity to lower GW frequencies, the entire BEC DM parameter space can be effectively probed by our new method in the near future

Einsatz multimedialer Präsentationstechniken am IPEK - Institut für Produktentwicklung der Universtität Karlsruhe (TH)

Am IPEK werden multimediale Lehr- und Lernformen sowohl Vorlesungen des Vor- und Hauptdiploms mit sehr hohen Studierendenzahlen (ca. 550 Studierende) als auch in Hauptfachvorlesungen mit relativ kleinen Gruppen (ca. 25 Studierende) umgesetzt. Die Lehre ist z.B. vollkommen vom herkömmlichen Tafelanschrieb gelöst und wird mit Hilfe eines Tablet-PC\u27s bzw. eines sog. Smart-Boards - einer berührungsempfindlichen Leinwand - durchgeführt, sodass Annotationen und Ergänzungen wahlweise direkt in die Präsentation eingefügt werden können oder auch auf einem "weißen Blatt" digital entwickelt werden können. Auch Videos, Animationen und gefilmte Modelle werden über spezielle Schnittstellen direkt in das projizierte Bild eingebunden. Dadurch findet ein didaktisch wertvoller Medienwechsel statt, der dem Präsentierenden die Möglichkeit gibt, die Lehre frei aufzubauen ohne sich von der Technik lenken lassen zu müssen und ohne den Studierenden den Rücken zudrehen zu müssen. Da einige Vorlesungen per Videoübertragung in einen weiteren Hörsaal übertragen werden müssen, ist somit auch für die Studierenden im zweiten Hörsaal die Möglichkeit gegeben, alle Informationen aufzunehmen. Weiterhin besteht die Möglichkeit, die in der Lehrveranstaltung hinzugefügten Notizen abzuspeichern und durch eine strukturierte Datenablage dauerhaft verfügbar zu machen. Durch eine vollständige Klassifizierung und Modularisierung der Lehrveranstaltungen und eine geeignete Form der Datenablage ist ein durchgängiger Zugriff auf die jeweils aktuellen Daten gegeben. Dies ist besonders wichtig, da viele der Grundlagenmodule für verschiedene Lehrveranstaltungen genutzt werden können und ständig durch aktuelle Forschungsergebnisse ergänzt werden. Die Erfolge des ständig erweiterten und verbesserten Medieneinsatzes in der Lehre des IPEK werden im Rahmen von Evaluationen erfasst und ausgewertet. Hierbei zeigt sich eine klare Tendenz zu einem tieferen Verständnis für komplexe Zusammenhänge und zu einer größeren Zufriedenheit der Studierenden mit der Art der Darstellung von Lehrinhalten

Room temperature organic exciton-polariton condensate in a lattice

Funding: The Würzburg group acknowledges financial support from the state of Bavaria. We also thank the Würzburg–Dresden Cluster of Excellence ct.qmat for financial support.Interacting Bosons in artificial lattices have emerged as a modern platform to explore collective manybody phenomena and exotic phases of matter as well as to enable advanced on-chip simulators. On chip, exciton–polaritons emerged as a promising system to implement and study bosonic non-linear systems in lattices, demanding cryogenic temperatures. We discuss an experiment conducted on a polaritonic lattice at ambient conditions: We utilize fluorescent proteins providing ultra-stable Frenkel excitons. Their soft nature allows for mechanically shaping them in the photonic lattice. We demonstrate controlled loading of the coherent condensate in distinct orbital lattice modes of different symmetries. Finally, we explore the self-localization of the condensate in a gap-state, driven by the interplay of effective interaction and negative effective mass in our lattice. We believe that this work establishes organic polaritons as a serious contender to the well-established GaAs platform for a wide range of applications relying on coherent Bosons in lattices.Publisher PDFPeer reviewe

Going to the exclusive show : exhibition strategies and moviegoing memories of Disneys animated feature films in Ghent (1937-1982)

This is a case study of the exploitation and experience of Disney's animated feature films from the 1930s to the 1980s in Ghent (Belgium). It is a historical study of programming practices and financial strategies which constructed childhood memories on watching Disney. The study is a contribution to a historical understanding of the implications of global distribution of film as cultural products and the counter pull of localism. Using a multi-method approach, the argument is made that the scarce screenings were strategically programmed to uplift the moviegoing experience into something out of the ordinary in everyday life. Programming and revenue data characterize the screenings as exclusive and generating high intakes. Consequently, the remembered screenings did not exhale an easy accessible social status nor an image of pervasiveness of popular childhood film, contradictory to conventional accounts of Disney's ubiquity in popular culture

A pathogenic skin fungus and sloughing exacerbate cutaneous water loss in amphibians

Batrachochytrium dendrobatidis (Bd) is a pathogenic fungus that causes the cutaneous, infectious disease chytridiomycosis and has been implicated in population declines of numerous anuran species worldwide. Proximate cause of death by chytridiomycosis is asystolic cardiac arrest as a consequence of severe disruption to electrolyte balance. Animals heavily infected with Bd also experience a disruption to their skin sloughing regime, indicating that core functions of the skin, such as water retention, may be severely impacted. This study examined how skin sloughing, body size and Bd infection interact to influence water loss rates in five Australian frog species: Litoria caerulea, Limnodynastes peronii, Lechriodus fletcheri, Limnodynastes tasmaniensis and Platyplectrum ornatum. Rates of water loss more than doubled during sloughing in L. caerulea. During active periods across all species, water loss rates were on average 232% higher in Bd infected frogs than in uninfected frogs. This indicates that dehydration stress may be a significant factor contributing to the morbidity of severely Bd infected anurans, a symptom that is then exacerbated by an increased rate of sloughing. When taking size into account, smaller and/or juvenile anurans may be more at risk from dehydration due to Bd infection, as they lose a greater amount of water and slough more frequently than adults. This may in part explain the higher mortality rates typical for small and juvenile frogs infected with Bd. Understanding how Bd affects the core functions of the skin, including rates of water loss, can improve our predictions of disease outcome in amphibians