OpenAccess

Ultralight bosons near rotating black holes can undergo significant growth through superradiant energy extraction, potentially reaching field values close to the Planck scale and transforming black holes into effective transducers for these fields. The interaction between boson fields and fermions may lead to parametric production or Schwinger pair production of fermions, with efficiencies significantly exceeding those of perturbative decay processes. [...]

Synchrotron radiation sources and free-electron lasers have revolutionised the study of matter and biological systems by providing unique combinations of radiation pulse characteristics. Although these two types of facilities differ fundamentally in terms of pulses time scales, coherence properties, and (peak) brilliance, each offers an exceptional mix of these features. [...]

Soft X-ray irradiation of molecules causes electronic core-level vacancies through photoelectron emission. In light elements, such as C, N, or O, which are abundant in the biosphere, these vacancies predominantly decay by Auger emission, leading inevitably to dissociative multiply charged states [...]

Die Untersuchung der Wechselwirkung von Röntgenstrahlen mit biorelevanter Materie ist ein anhaltendes und weitverbreitetes Forschungsfeld. Obwohl die makroskopischen Folgen dieser Wechselwirkung bereits weitgehend verstanden sind, ist unser Verständnis der Prozesse auf molekularer Ebene noch sehr unzureichend. [...]

The aim of the project openCost is to create a technical infrastructure that makes publication costs freely accessible and exchangeable via standardized interfaces and formats. This is supposed to enable cost transparency on an institutional, national, and international level.To achieve this, we are developing a standardized metadata schema to record, retrieve and map all publication costs of a scientific institution in a structured form. [...]

The structural and dynamical properties of soft-matter systems play an important role in crystallization and nucleation theory. Despite their significance, the dynamical properties are still poorly understood because of experimental constraints and the requirement of performing measurements with high spatial and temporal resolution. [...]

New coordination complexes of 3d metals that possess photoactive metal-centered (MC) excited states arepromising targets for optical applications and photocatalysis. Ultrafast spectroscopy plays an important rolein elucidating the photophysical mechanisms that underlie photochemical activity. [...]

Retained austenite is an essential phase in various types of steel due to its ability to positively influence mechanicalproperties. However, in the research field of high-strength weld metals, it is typically considered only aspart of martensite-austenite constituents. [...]

The paper presents in-depth studies of the dielectric properties and conduction dynamics of Dy-doped CaBaFe$_4$⁢O$_7$ which is a recently characterized magnetoelectric material with strong potentials for technological applications as it shows a near-room-temperature ferrimagnetic transition along with strong ferrimagnetic moment, and gigantic electric polarization change. This work demonstrates the direct correlation of the dielectric and electrical transport properties of Ca$_{1−𝑥}$⁢Dy$_𝑥$⁢BaFe$_4$⁢O$_7$ (𝑥=0, 0.01, 0.03, and 0.05) with structural distortion through various dc, ac conduction, high-energy x-ray diffraction studies, and modeling of the data [...]

ISI oder SCOPUS Publikationen mit DESY Autor sowie alle Dissertationen mit DESY Beteiligung