Bosonic Preheating in Left-Right-Symmetric SUSY GUTs

We investigate the possibility of a bosonic preheating in the simplest model of supersymmetric Hybridinflation (F-term inflation), which was considered first by Dvali et al. Here the inflationary superpotential is of the O'Raifertaigh-Witten type. The end of inflation is related to a non-thermal phase transition, which in the context of left-right symmetric models lowers the rank of the gauge group. Using the homogeneous classical field ansatz for the appearing condensates, our results indicate that the parametric creation of bosonic particles does not occure in the model under consideration.Comment: 14 pages, 6 figure

SO(10)-GUT Coherent Baryogenesis

A model for GUT baryogenesis, coherent baryogenesis within the framework of supersymmetric SO(10), is considered. In particular, we discuss the Barr-Raby model, where at the end of hybrid infl ation charge asymmetries can be created through the time-dependent higgsino-gaugino mixing mass matrix. These asymmetries are processed to Standard Model matter through decays via nonrenormalizable (B-L)-violating operators. We find that a baryon asymmetry in accordance with observation can be generated. An appendix is devoted to provide useful formulas and concrete examples for calculations within SO(10).Comment: 30 pages, 3 figure

Digitalisierung der Hochschullehre - ein Erfahrungsbericht über den Einsatz von Live-Votings und onlinebasierten Selbstkontrolltests

Größere Lehrveranstaltungen an der Universität gehen zwangsläufig mit Herausforderungen einher. Deren Rahmenbedingungen wirken sich negativ auf die Interaktion zwischen Dozenten und den Studierenden aus. Dadurch erhält die Lehrperson kein valides Feedback von den Hörern, ob die Vorgehensgeschwindigkeit angemessen ist und inwiefern Verständnisschwierigkeiten auftreten. Hinzu kommt ein heterogenes Publikum hinsichtlich des Vorwissens und Studienfortschritts. Um dem entgegenzuwirken, hat sich der Einsatz von zwei digitalen Lehrinstrumenten bewährt. Live-Votings geben den Dozenten während der Veranstaltung direkte Rückmeldung zu etwaigen Wissenslücken bei einem Großteil der Studierenden. Online-Tests mit dem Zweck der Selbstkontrolle ergänzen die Präsenzveranstaltungen um ein zeitlich flexibilisiertes Lehrangebot und versprechen eine verbesserte Klausurvorbereitung

The Pointing System of the Herschel Space Observatory. Description, Calibration, Performance and Improvements

We present the activities carried out to calibrate and characterise the performance of the elements of attitude control and measurement on board the Herschel spacecraft. The main calibration parameters and the evolution of the indicators of the pointing performance are described, from the initial values derived from the observations carried out in the performance verification phase to those attained in the last year and half of mission, an absolute pointing error around or even below 1 arcsec, a spatial relative pointing error of some 1 arcsec and a pointing stability below 0.2 arsec. The actions carried out at the ground segment to improve the spacecraft pointing measurements are outlined. On-going and future developments towards a final refinement of the Herschel astrometry are also summarised. A brief description of the different components of the attitude control and measurement system (both in the space and in the ground segments) is also given for reference. We stress the importance of the cooperation between the different actors (scientists, flight dynamics and systems engineers, attitude control and measurement hardware designers, star-tracker manufacturers, etc.) to attain the final level of performance.Comment: 28 pages, 8 figures, accepted for publication in Experimental Astronom

Introduction to the nonequilibrium functional renormalization group

In these lectures we introduce the functional renormalization group out of equilibrium. While in thermal equilibrium typically a Euclidean formulation is adequate, nonequilibrium properties require real-time descriptions. For quantum systems specified by a given density matrix at initial time, a generating functional for real-time correlation functions can be written down using the Schwinger-Keldysh closed time path. This can be used to construct a nonequilibrium functional renormalization group along similar lines as for Euclidean field theories in thermal equilibrium. Important differences include the absence of a fluctuation-dissipation relation for general out-of-equilibrium situations. The nonequilibrium renormalization group takes on a particularly simple form at a fixed point, where the corresponding scale-invariant system becomes independent of the details of the initial density matrix. We discuss some basic examples, for which we derive a hierarchy of fixed point solutions with increasing complexity from vacuum and thermal equilibrium to nonequilibrium. The latter solutions are then associated to the phenomenon of turbulence in quantum field theory.Comment: Lectures given at the 49th Schladming Winter School `Physics at all scales: The Renormalization Group' (to appear in the proceedings); 24 pages, 3 figure

The nature of Long-GRB host galaxies from chemical abundances

Gamma-ray bursts (GRBs) are the most energetic events after the Big Bang and they have been observed up to very high redshift. By means of measures of chemical abundances now available for the galaxies hosting such events,thought to originate from the explosion of very powerful supernovae (Type Ib/c), we have the opportunity to study the nature of these host galaxies. The aim of this paper is to identify the hosts of Long GRBs (LGRBs) observed both at low and high redshift to see whether the hosts can be galaxies of the same type observed at different cosmic epochs. We adopt detailed chemical evolution models for galaxies of different morphological type (ellipticals, spirals, irregulars) which follow the time evolution of the abundances of several chemical elements (H, He, $\alpha$-elements, Fe), and compare the results with the observed abundances and abundance ratios in galaxies hosting LGRBs. We find that the abundances and abundance ratios predicted by models devised for typical irregular galaxies can well fit the abundances in the hosts both at high and low redshift. We also find that the predicted Type Ib/c supernova rate for irregulars is in good agreement with observations. Models for spirals and particularly ellipticals do not fit the high-redshift hosts of LGRBs (DLA systems) nor the low redshift hosts: in particular, ellipticals cannot possibly be the hosts of gamma-ray-bursts at low redshift since they do not show any star formation, and therefore no supernovae Ib/c. We conclude that the observed abundance and abundance ratios in LGRBs hosts suggest that these hosts are irregular galaxies both at high and low redshift thus showing that the host galaxies belong to in an evolutionary sequence.Comment: 8 pages, 9 figures, two references adde

Depletion of B2 but Not B1a B Cells in BAFF Receptor-Deficient ApoE−/− Mice Attenuates Atherosclerosis by Potently Ameliorating Arterial Inflammation

We have recently identified conventional B2 cells as atherogenic and B1a cells as atheroprotective in hypercholesterolemic ApoE−/− mice. Here, we examined the development of atherosclerosis in BAFF-R deficient ApoE−/− mice because B2 cells but not B1a cells are selectively depleted in BAFF-R deficient mice. We fed BAFF-R−/− ApoE−/− (BaffR.ApoE DKO) and BAFF-R+/+ApoE−/− (ApoE KO) mice a high fat diet (HFD) for 8-weeks. B2 cells were significantly reduced by 82%, 81%, 94%, 72% in blood, peritoneal fluid, spleen and peripheral lymph nodes respectively; while B1a cells and non-B lymphocytes were unaffected. Aortic atherosclerotic lesions assessed by oil red-O stained-lipid accumulation and CD68+ macrophage accumulation were decreased by 44% and 50% respectively. B cells were absent in atherosclerotic lesions of BaffR.ApoE DKO mice as were IgG1 and IgG2a immunoglobulins produced by B2 cells, despite low but measurable numbers of B2 cells and IgG1 and IgG2a immunoglobulin concentrations in plasma. Plasma IgM and IgM deposits in atherosclerotic lesions were also reduced. BAFF-R deficiency in ApoE−/− mice was also associated with a reduced expression of VCAM-1 and fewer macrophages, dendritic cells, CD4+ and CD8+ T cell infiltrates and PCNA+ cells in lesions. The expression of proinflammatory cytokines, TNF-α, IL1-β and proinflammatory chemokine MCP-1 was also reduced. Body weight and plasma cholesterols were unaffected in BaffR.ApoE DKO mice. Our data indicate that B2 cells are important contributors to the development of atherosclerosis and that targeting the BAFF-R to specifically reduce atherogenic B2 cell numbers while preserving atheroprotective B1a cell numbers may be a potential therapeutic strategy to reduce atherosclerosis by potently reducing arterial inflammation

Empfehlungen der Ständigen Impfkommission (STIKO) und der Deutschen Gesellschaft für Tropenmedizin, Reisemedizin und Globale Gesundheit e.V. (DTG) zu Reiseimpfungen.

Die STIKO empfiehlt Reiseimpfungen zum individuellen Schutz Reisender mit einem Expositionsrisiko gegenüber bestimmten impfpräventablen Erkrankungen und um den Import von Infektionserregern in das bereiste Land oder bei Rückreise nach Deutschland zu verhindern. Die im Epidemiologischen Bulletin 14/2024 veröffentlichten Empfehlungen zu Reiseimpfungen wurden von der STIKO-AG Reiseimpfungen in Zusammenarbeit mit externen Expertinnen und Experten erarbeitet. Enthalten ist dabei u. a. ein neues Kapitel zum Dengue-Virus mit Risikokarte. Aktualisiert wurden u. a. das Kapitel zu COVID-19, die Literaturliste und Reisekarten zu Influenza, Japanische und zeckenübertragene Enzephalitis sowie Tollwut

Empfehlungen der Ständigen Impfkommission (STIKO) und der Deutschen Gesellschaft für Tropenmedizin, Reisemedizin und Globale Gesundheit e.V. (DTG) zu Reiseimpfungen.

Die STIKO empfiehlt Reiseimpfungen zum individuellen Schutz Reisender mit einem Expositionsrisiko gegenüber bestimmten impfpräventablen Erkrankungen und um den Import von Infektionserregern in das bereiste Land oder bei Rückreise nach Deutschland zu verhindern. Die im Epidemiologischen Bulletin 14/2024 veröffentlichten Empfehlungen zu Reiseimpfungen wurden von der STIKO-AG Reiseimpfungen in Zusammenarbeit mit externen Expertinnen und Experten erarbeitet. Enthalten ist dabei u. a. ein neues Kapitel zum Dengue-Virus mit Risikokarte. Aktualisiert wurden u. a. das Kapitel zu COVID-19, die Literaturliste und Reisekarten zu Influenza, Japanische und zeckenübertragene Enzephalitis sowie Tollwut