Reheating after Supercooling in the Chiral Phase Transition

The chirally symmetric quark-gluon plasma produced in energetic heavy-ion collisions is predicted to supercool at the late stages of its evolution. The thermal energy is then transformed into the potential energy associated with an energetically unfavorable field configuration. Since the system is in an unstable state it eventually rolls down to the true minimum of the effective chiral potential. When this motion is described in terms of the sigma-model, we find that the energy of the coherent $\sigma-$field is very efficiently converted into pionic excitations due to anharmonic oscillations around this minimum. The system is expected to partially thermalize before its disintegration.Comment: Final version accepted for publication, 8 pages, REVTe

Convex integration for Lipschitz mappings and counterexamples to regularity

We study Lispchitz solutions of partial differential relations $\nabla u\in K$, where $u$ is a vector-valued function in an open subset of $R^n$. In some cases the set of solutions turns out to be surprisingly large. The general theory is then used to construct counter-examples to regularity of solutions of Euler-Lagrange systems satisfying classical ellipticity conditions.Comment: 28 pages published versio

Interpolation with circular basis functions

In this paper we consider basis function methods for solving the problem of interpolating data over distinct points on the unit circle. In the special case where the points are equally spaced we can appeal to the theory of circulant matrices which enables an investigation into the stability and accuracy of the method. This work is a further extension and application of the research of Cheney, Light and Xu ([W.A. Light and E.W. Cheney, J. Math. Anal. Appl., 168:110–130, 1992] and [Y. Xu and E.W. Cheney, Computers Math. Applic., 24:201–215, 1992]) from the early nineties

Microscopic Description of Deeply Virtual Compton Scattering off Spin-0 Nuclei

We evaluate within a microscopic calculation the contributions of both coherent and incoherent deeply virtual Compton scattering from a spin-0 nucleus. The coherent contribution is obtained when the target nucleus recoils as a whole, whereas for incoherent scattering break-up configurations for the final nucleus into a an outgoing nucleon and an $A-1$ system are considered. The two processes encode different characteristics of generalized parton distributions.Comment: 7 pages, 3 figure

Isotopic ratios at z=0.68 from molecular absorption lines toward B 0218+357

Isotopic ratios of heavy elements are a key signature of the nucleosynthesis processes in stellar interiors. The contribution of successive generations of stars to the metal enrichment of the Universe is imprinted on the evolution of isotopic ratios over time. We investigate the isotopic ratios of carbon, nitrogen, oxygen, and sulfur through millimeter molecular absorption lines arising in the z=0.68 absorber toward the blazar B 0218+357. We find that these ratios differ from those observed in the Galactic interstellar medium, but are remarkably close to those in the only other source at intermediate redshift for which isotopic ratios have been measured to date, the z=0.89 absorber in front of PKS1830-211. The isotopic ratios in these two absorbers should reflect enrichment mostly from massive stars, and they are indeed close to the values observed toward local starburst galaxies. Our measurements set constraints on nucleosynthesis and chemical evolution models.Comment: Accepted for publication in Astronomy & Astrophysics; 10 pages, 9 figure

The correlation between values-based leadership and economic success: An empirical evaluation within selected German cooperative banks and related policy implications

We are living in a society which is characterised by a permanent developing knowledge culture. The emergence of this megatrend among others, in combination with the financial crisis started in 2007 is the basis of the discussion about values and their impact on economic success. This study explores the links between values, which promote leadership, especially cooperative values, and economic success. The thesis is based on an online survey with all cooperative banks in Germany with an individual balance sheet totals over 1500 million Euro. These banks represent the greatest cooperative banks in Germany and their employees were invited to answer a questionnaire in order to analyse if cooperative values are part of everyday leadership and are perceived accordingly. The examined values were fairness, confidence, certainty, competence, reliability, individuality, common ground, respect, partnership, responsibility and solidarity. These values were set in correlation to financial figures: capital adequacy, asset quality, management efficiency, earnings quality and liquidity management. In addition to that the questionnaire of the online survey contained questions about performance appraisal systems including feedback systems for executives. The concept of values-based leadership and economic success measured in Key Performance Indicators formed the conceptual framework as presented in the literature review. Beyond that, this research follows the fundamental philosophy ‘critical theory’, because critical theory as a social theory is oriented toward critiquing society as a whole or like in this research project a part of our society. The study shows first small indications about the relationships between cooperative management values and business key figures. Correlation analysis was one of the main statistical analysis method of the study, because it measures the relationship between two items. In this case values and financial figures. In addition, various regression analyses were carried out. The aim of regression analysis is to determine the relationships between a dependent variable (financial figures) on the one hand and several explanatory variables (cooperative values) on the other. The elaborations in this study indicate that values-based leadership might have a positive influence on economic success. Organisations could be able to improve their results if they follow the concept of values-based leadership or even the cooperative values management style. The findings of this study might have important implications for those training, coaching or selecting executives, those intending to take a leadership position or who already are leaders, the organisations within values-based leadership is put into focus and for other researchers who want to build on the results. Thus, this study contributes to both practice and knowledge

Submillimeter polarization and variability of quasar PKS 1830-211

Polarization from active galactic nuclei is interpreted as a signpost of the role of magnetic fields in the launch and collimation of their relativistic radio jets. Here, we report the detection of a clear polarization signal from ALMA observations of the gravitationally lensed quasar PKS 1830-211 at submillimeter wavelengths (Band 9, 650 GHz). Applying a differential-polarimetry technique to the two compact lensed images of the quasar, we estimate a fractional polarization of ~5% for one lensed image, while the other appears nearly unpolarized, which implies that the polarization activity varies on a timescale of a few weeks. With additional ALMA Band 7 and 8 (between 300-500 GHz) concomitant data, we constrain a Faraday rotation of a few $10^5$ rad m$^{-2}$. We also observe flux-density variability of ~10% within one hour in Band 9. This work illustrates that a differential analysis can extract high-accuracy information (flux-density ratio and polarimetry) free of calibration issues from resolved sources in the submillimeter domain.Comment: 7 pages, 6 figures, accepted for publications in A&