Density of states of a damped quantum oscillator

We calculate the density of states of a damped quantum-mechanical harmonic oscillator which is described by a Caldeira-Leggett type model with Ohmic dissipation and a Drude-like cutoff. From the exact expression for the associated partition function, we derive the asymptotic behavior of the density of states using Tauberian theorems. An effective algorithm to evaluate the density of states is presented and examples are given. It is pointed out that the calculated density of states is an experimentally accessible quantity

The gravitational wave burst signal from core collapse of rotating stars

We present results from detailed general relativistic simulations of stellar core collapse to a proto-neutron star, using two different microphysical nonzero-temperature nuclear equations of state as well as an approximate description of deleptonization during the collapse phase. Investigating a wide variety of rotation rates and profiles as well as masses of the progenitor stars and both equations of state, we confirm in this very general setup the recent finding that a generic gravitational wave burst signal is associated with core bounce, already known as type I in the literature. The previously suggested type II (or "multiple-bounce") waveform morphology does not occur. Despite this reduction to a single waveform type, we demonstrate that it is still possible to constrain the progenitor and postbounce rotation based on a combination of the maximum signal amplitude and the peak frequency of the emitted gravitational wave burst. Our models include to sufficient accuracy the currently known necessary physics for the collapse and bounce phase of core-collapse supernovae, yielding accurate and reliable gravitational wave signal templates for gravitational wave data analysis. In addition, we assess the possiblity of nonaxisymmetric instabilities in rotating nascent proto-neutron stars. We find strong evidence that in an iron core-collapse event the postbounce core cannot reach sufficiently rapid rotation to become subject to a classical bar-mode instability. However, many of our postbounce core models exhibit sufficiently rapid and differential rotation to become subject to the recently discovered dynamical instability at low rotation rates.Comment: 28 pages, 23 figures, minor change

Infrastructure for Detector Research and Development towards the International Linear Collider

The EUDET-project was launched to create an infrastructure for developing and testing new and advanced detector technologies to be used at a future linear collider. The aim was to make possible experimentation and analysis of data for institutes, which otherwise could not be realized due to lack of resources. The infrastructure comprised an analysis and software network, and instrumentation infrastructures for tracking detectors as well as for calorimetry.Comment: 54 pages, 48 picture

Effects of atmospheric and climate change at the timberline of the Central European Alps

• This review considers potential effects of atmospheric change and climate warming within the timberline ecotone of the Central European Alps. After focusing on the impacts of ozone (O$_{3}$) and rising atmospheric CO$_{2}$ concentration, effects of climate warming on the carbon and water balance of timberline trees and forests will be outlined towards conclusions about changes in tree growth and treeline dynamics. • Presently, ambient ground-level O$_{3}$ concentrations do not exert crucial stress on adult conifers at the timberline of the Central European Alps. In response to elevated atmospheric CO$_{2}$ Larix decidua showed growth increase, whereas no such response was found in Pinus uncinata. Overall climate warming appears as the factor responsible for the observed growth stimulation of timberline trees. • Increased seedling re-establishment in the Central European Alps however, resulted from invasion into potential habitats rather than upward migration due to climate change, although seedlings will only reach tree size upon successful coupling with the atmosphere and thus loosing the beneficial microclimate of low stature vegetation. • In conclusion, future climate extremes are more likely than the gradual temperature increase to control treeline dynamics in the Central European Alps.Effets des changements atmosphériques et des changements climatiques à la limite supérieure de la forêt en Europe dans les Alpes centrales. • Cette étude examine les effets potentiels des changements atmosphériques et du réchauffement climatique au sein de l'écotone que constitue la limite supérieure de la forêt dans les Alpes centrales en Europe. Après avoir mis l'accent sur les effets de l'ozone (O$_{3}$) et de l'augmentation des concentrations atmosphériques du CO$_{2}$, les effets du réchauffement climatique sur le bilan de carbone et le bilan hydrique des arbres et des forêts à la limite supérieure de la forêt seront présentés en vue de tirer des conclusions sur l'évolution de la croissance des arbres et sur les dynamiques de la limite supérieure de la forêt. • Actuellement, les concentrations en O$_{3}$ de l'air ambiant au niveau du sol n'exercent pas un stress critique sur les arbres adultes à la limite supérieure de la forêt dans les Alpes centrales en Europe. En réponse à des concentrations élevées en CO$_{2}$ Larix decidua a montré une augmentation de la croissance, alors qu'une telle réponse n'a pas été trouvée chez Pinus uncinata. Globalement, le réchauffement climatique apparaît être le facteur responsable de la stimulation de la croissance observée chez les arbres à la limite supérieure de la forêt. • Toutefois, l'augmentation de la réinstallation des semis dans les Alpes centrales en Europe est le résultats de l'invasion d'habitats potentiels plutôt qu'une migration en altitude due aux changements climatiques, bien que les semis atteindront seulement la taille des arbres après un couplage réussit avec l'atmosphère et donc perdant le microclimat favorable d'une végétation basse. • En conclusion, les phénomènes climatiques extrêmes futurs sont plus susceptibles de contrôler les dynamiques de limite supérieure de la forêt, que l'augmentation progressive de la température dans les Alpes centrales en Europe

An epichromatin epitope: Persistence in the cell cycle and conservation in evolution

Interphase nuclear architecture is disrupted and rapidly reformed with each cell division cycle. Successive cell generations exhibit a “memory” of this nuclear architecture, as well as for gene expression. Furthermore, many features of nuclear and mitotic chromosome structure are recognizably species and tissue specific. We wish to know what properties of the underlying chromatin structure may determine these conserved features of nuclear architecture. Employing a particular mouse autoimmune anti-nucleosome monoclonal antibody (PL2-6), combined with deconvolution immunofluorescence microscopy, we present evidence for a unique epitope (involving a ternary complex of histones H2A and H2B and DNA) which is localized only at the exterior chromatin surface of interphase nuclei and mitotic chromosomes in mammalian, invertebrate and plant systems. As only the surface chromatin region is identified with antibody PL2-6, we have assigned it the name “epichromatin”. We describe an “epichromatin hypothesis”, suggesting that epichromatin may have a unique evolutionary conserved conformation which facilitates interaction with the reforming post-mitotic nuclear envelope and a rapid return of interphase nuclear architecture