16238417
Gravitational collapse and the formation of black holes for the spherically symmetric Einstein-Vlasov system
We review results on the spherically symmetric, asymptotically flat Einstein-Vlasov system. We focus on a recent result where we found explicit conditions on the initial data which guarantee the formation of a black hole in the evolution. Among these data there are data such that the corresponding solutions exist globally in Schwarzschild coordinates. We put these results into a more general context, and we include arguments which show that the spacetimes we obtain satisfy the weak cosmic censorship conjecture and contain a black hole in the sense of suitable mathematical definitions of these concepts which are available in the literature.
53967767
Existence of Axially Symmetric Static Solutions of the Einstein-Vlasov System
We prove the existence of static, asymptotically flat non-vacuum spacetimes with axial symmetry where the matter is modeled as a collisionless gas. The axially symmetric solutions of the resulting Einstein-Vlasov system are obtained via the implicit function theorem by perturbing off a suitable spherically symmetric steady state of the Vlasov-Poisson system.
109845469
Virtualized Batch Worker Nodes: Conception and Integration in HPC Environments
There are various use cases where one has to separate user environments from the provided machine hardware, operating system or software setup on a cluster. To achieve this, a lightweight implementation of dynamically virtualized worker nodes in common batch systems is presented. Additionally, a summary of experiences and performance measurements obtained by running such a virtualized cluster, shared between nine different departments of the Karlsruhe Institute of Technology, is presented.
121889238
Antiproton-proton annihilation at rest into two mesons
Abstract Branching ratios for antiproton-proton annihilations at rest into two mesons are given. The data were obtained at LEAR by stopping antiprotons in a liquid hydrogen target. Both charged and neutral annihilation products were detected in the Crystal Barrel detector. Representative data are presented, and their bearing on the general picture of annihilation dynamics is discussed. In addition, preliminary branching ratios for two-body radiative annihilations are given.
122284184
Parametric optimization with evolutionary strategies in particle physics
Abstract Evolutionary strategies provide a generic means to find optimum solutions for large-scale numerical problems. The EVA library, an implementation of parallel Evolutionary Algorithms, adds the possibility to run the optimization in parallel on devices ranging from multi-processor machines over clusters to the world wide grid. This paper discusses the application of the EVA library to two distinct computationally expensive physics problems—the optimization of particle signals in histograms and the minimization procedure involved in analysing Dalitz plots.