Inflation with Fayet-Iliopoulos Terms

Two of the most attractive realizations of inflation in supergravity are based upon the presence of a constant Fayet-Iliopoulos (FI) term. In D-term hybrid inflation it is the FI term itself which sets the energy scale of inflation. Alternatively, the breaking of a U(1) symmetry induced by the FI term can dynamically generate the quadratic potential of chaotic inflation. The purpose of this note is to study the possible UV embedding of these schemes in terms of the `field-dependent FI term' related to a string modulus field which is stabilized by a non-perturbative superpotential. We find that in settings where the FI term drives inflation, gauge invariance prevents a decoupling of the modulus from the inflationary dynamics. The resulting inflation models generically contain additional dynamical degrees of freedom compared to D-term hybrid inflation. However, the dynamical realization of chaotic inflation can be obtained in complete analogy to the case of a constant FI term. We present a simple string-inspired toy model of this type.Comment: 20 pages, accepted for publication in PR

Supersymmetric Moduli Stabilization and High-Scale Inflation

We study the back-reaction of moduli fields on the inflaton potential in generic models of F-term inflation. We derive the moduli corrections as a power series in the ratio of Hubble scale and modulus mass. The general result is illustrated with two examples, hybrid inflation and chaotic inflation. We find that in both cases the decoupling of moduli dynamics and inflation requires moduli masses close to the scale of grand unification. For smaller moduli masses the CMB observables are strongly affected.Comment: 5 page

UV Corrections in Sgoldstino-less Inflation

We study the embedding of inflation with nilpotent multiplets in supergravity, in particular the decoupling of the sgoldstino scalar field. Instead of being imposed by hand, the nilpotency constraint on the goldstino multiplet arises in the low energy-effective theory by integrating out heavy degrees of freedom. We present explicit supergravity models in which a large but finite sgoldstino mass arises from Yukawa or gauge interactions. In both cases the inflaton potential receives two types of corrections. One is from the backreaction of the sgoldstino, the other from the heavy fields generating its mass. We show that these scale oppositely with the Volkov-Akulov cut-off scale, which makes a consistent decoupling of the sgoldstino nontrivial. Still, we identify a parameter window in which sgoldstino-less inflation can take place, up to corrections which flatten the inflaton potential.Comment: 7 pages, 1 figure. Comments added, published versio

A Euro Rescue Plan

Euro; Wechselkursrisiko; Gesamtwirtschaftliche Liquidität; Europäische Wirtschafts- und Währungsunion; Geldpolitik; Wirkungsanalyse; EU-Staaten

WAY-KEY – smarter Mobilitätsassistent für Menschen mit Demenzerkrankung

In Österreich sind etwa 1,2 Prozent der Bevölkerung an Demenz erkrankt, was einer Gesamtzahl von rund 100.000 Personen entspricht. Mit zunehmendem Alter nimmt auch die Prävalenz stark zu, was im Zuge der demographischen Alterung daher einen starken Anstieg der Zahl der Betroffenen in der Zukunft erwarten lässt. Der Erhalt von und die Motivation zur Mobilität wirkt aus mehreren Gründen zumindest verzögernd auf den Verlauf dementieller Erkrankungen. Mangelnde Bewegung ist laut Norton et al. jener Risikofaktor, der den meisten vermeidbaren Alzheimer-Demenz-Fällen in den Vereinigten Staaten von Amerika (USA) und Europa zugrunde liegt. Der österreichische Demenzbericht nennt als Risikofaktor bei der Entwicklung demenzieller Erkrankungen: „... weniger als 20 Minuten flotte Bewegung an drei oder mehr Tagen pro Woche oder weniger als 30 Minuten moderate Bewegung an fünf oder mehr Tagen pro Woche...“. Da Mobilität bei Demenz aber auch Risken wie Verlorengehen und Stürze mit sich bringt, zielen bisherige technische Lösungen in erster Linie darauf ab, die Mobilität demenziell erkrankter Menschen von außen her zu überwachen und einzuschränken oder zu verhindern. Sie unterstützen damit in erster Linie Pflegepersonal oder Angehörige und machen Personen mit Demenz zum passiven Teil der Wirkungskette. Dort, wo versucht wurde, ältere Menschen selbst durch technologische Lösungen mobil zu erhalten, wurde bisher auf Smartphones bzw. Smartwatches gesetzt, deren Handhabung demente Personen jedoch überfordert. Das WAY-KEY-Konsortium möchte existierende technische (Teil-)Lösungen der Firmenpartner in einem stark partizipatorisch ausgelegten Designprozess mit Hilfe der Wissenschaftspartner für demenziell Erkrankte zur Förderung ihrer Mobilität nutzbar machen

Challenges for Large-Field Inflation and Moduli Stabilization

We analyze the interplay between K\"ahler moduli stabilization and chaotic inflation in supergravity. While heavy moduli decouple from inflation in the supersymmetric limit, supersymmetry breaking generically introduces non-decoupling effects. These lead to inflation driven by a soft mass term, $m_\varphi^2 \sim m m_{3/2}$, where $m$ is a supersymmetric mass parameter. This scenario needs no stabilizer field, but the stability of moduli during inflation imposes a large supersymmetry breaking scale, $m_{3/2} \gg H$, and a careful choice of initial conditions. This is illustrated in three prominent examples of moduli stabilization: KKLT stabilization, K\"ahler Uplifting, and the Large Volume Scenario. Remarkably, all models have a universal effective inflaton potential which is flattened compared to quadratic inflation. Hence, they share universal predictions for the CMB observables, in particular a lower bound on the tensor-to-scalar ratio, $r \gtrsim 0.05$.Comment: 44+1 pages, 6 figures, minor modifications, references adde

The myeloid expressed EF-hand proteins display a diverse pattern of lipid raft association

AbstractEF-hand proteins are known to translocate to membranes, suggesting that they are involved in signaling events located in the cell membrane. Many proteins involved in signaling events associate cholesterol rich membrane domains, so called lipid rafts, which serve as platforms for controlled protein–protein interaction. Here, we demonstrate that the myeloid expressed EF-hand proteins can be distinguished into three classes with respect to their membrane association. Grancalcin, a myeloid expressed penta EF-hand protein, is constitutively located in lipid rafts. S100A9 (MRP14) and S100A8 (MRP8) are translocated into detergent resistant lipid structures only after calcium activation of the neutrophils. However, the S100A9/A8 membrane association is cholesterol and sphingolipid independent. On the other hand, the association of S100A12 (EN-RAGE) and S100A6 (calcyclin) with membranes is detergent sensitive. These diverse affinities to lipid structures of the myeloid expressed EF-hand proteins most likely reflect their different functions in neutrophils