9,362 research outputs found
The Three-flavor chiral phase structure in hot and dense QCD matter
No full textSchaefer B-J, Wagner M. The Three-flavor chiral phase structure in hot and dense QCD matter. Phys.Rev. D. 2009;79(1):014018
Low-momentum hyperon-nucleon interactions
No full textSchaefer B-J, Wagner M, Wambach J, Kuo TTS, Brown GE. Low-momentum hyperon-nucleon interactions. Phys.Rev. 2006;73(1): 11001
FiFoSiM - an integrated tax benefit microsimulation and CGE model for Germany
No full textThis paper describes FiFoSiM, the integrated tax benefit microsimulation and computable general equilibrium (CGE) model of the Center of Public Economics at the University of Cologne. FiFoSiM consists of three main parts. The first part is a static tax benefit microsimulation module. The second part adds a behavioural component to the model; an econometrically estimated labour supply model. The third module is a CGE model which allows the user of FiFoSiM to assess the global economic effects of policy measures. Two specific features distinguish FiFoSiM from other tax benefit models: First, the simultaneous use of two databases for the tax benefit module and second, the linkage of the tax benefit model to a CGE model.FiFoSiM; microsimulation; CGE
QCD thermodynamics with effective models
No full textSchaefer B-J, Wagner M, Wambach J. QCD thermodynamics with effective models. In: PoS CPOD2009. 2009: 017
Building Boeing: Julius Earl Schaefer Wichita's lost aviation leader
No full textThesis (M.A.)-- Wichita State University, College of Liberal Arts and Sciences, Dept. of HistoryThis thesis covers the life and career of Julius Earl Schaefer. He was an aviation pioneer in Wichita, Kansas, whose legacy has been lost in the history of Wichita aviation. This thesis attempts to reveal his importance in shaping the aviation community of Wichita. Schaefer managed the largest plant in town, and he had the drive to help his community grow. He was on many different boards and committees within the city. One of the more influential was the Chamber of Commerce. Schaefer helped direct the goals of the Chamber as they tried to direct the goals of the city. The main focus of the thesis is on the production of the B-29s. Wichita is remembered for these planes, but without Schaefer they would not have been built here.
Many resources were used to piece together Schaefer's life. The Boeing-Stearman collection in the Department of Special Collections at Wichita State University provided much of the material on the company life. Other company documents, such as the Boeing Contact and Boeing Plane Talk help show what life at the plant was like. Finally, a major aid to this project was the documents provided by Schaefer's remaining family. These documents helped to fill in the early years of his life and round out the story
Long-term population trends in three grassland insect groups: a comparative analysis of 1951 and 2009
No full textDevelopment of farming practices has caused drastic changes in European agricultural landscapes during the past 50 years. As a consequence of these changes, insect diversity is widely expected to decline. We performed a comparative analysis with long-term data of three insect groups: Auchenorrhyncha, Heteroptera and Orthoptera. In 2009, we revisited nine grassland sites in northern Germany that were originally sampled in 1951 using the same techniques and during a similar time frame. We found that the insect community exhibited no consistent trends between years. Species richness of Auchenorrhyncha and Heteroptera increased on plot level as well as on landscape level but remained unchanged for Orthoptera. Abundance of Auchenorrhyncha and Orthoptera significantly decreased, while Heteroptera increased. There is a strong trend towards homogeneity in community composition for Heteroptera and a weak one for Auchenorrhyncha. The frequency and abundance of species preferring disturbed and/or eutrophic habitats increased, whereas the number of species preferring low-productive habitats declined. This trend is especially pronounced in Auchenorrhyncha. Generalistic species were more abundant in relative proportions as well as in absolute numbers. We hypothesize that these trends arise from alterations of Central European landscapes because of agricultural intensification over the last several decades
Nonperturbative landscape of the Mott-Hubbard transition: Multiple divergence lines around the critical endpoint
No full textWe analyze the highly nonperturbative regime surrounding the Mott-Hubbard metal-to-insulator transition (MIT) by means of dynamical mean field theory (DMFT) calculations at the two-particle level. By extending the results of Schaefer et al. [Phys. Rev. Lett. 110, 246405 (2013)] we show the existence of infinitely many lines in the phase diagram of the Hubbard model where the local Bethe-Salpeter equations, and the related irreducible vertex functions, become singular in the charge as well as the particle-particle channel. By comparing our numerical data for the Hubbard model with analytical calculations for exactly solvable systems of increasing complexity [disordered binary mixture (BM), Falicov-Kimball (FK), and atomic limit (AL)], we have (i) identified two different kinds of divergence lines; (ii) classified them in terms of the frequency structure of the associated singular eigenvectors; and (iii) investigated their relation to the emergence of multiple branches in the Luttinger-Ward functional. In this way, we could distinguish the situations where the multiple divergences simply reflect the emergence of an underlying, single energy scale nu* below which perturbation theory is no longer applicable, from those where the breakdown of perturbation theory affects, not trivially, different energy regimes. Finally, we discuss the implications of our results on the theoretical understanding of the nonperturbative physics around the MIT and for future developments of many-body algorithms applicable in this regime
On the efficient computation of high-order derivatives for implicitly defined functions
No full textWagner M, Walther A, Schaefer B-J. On the efficient computation of high-order derivatives for implicitly defined functions. Comput.Phys.Commun. 2010;181(4):756-764
QCD Thermodynamics: Confronting the Polyakov-Quark-Meson Model with Lattice QCD
No full textWambach J, Schaefer B-J, Wagner M. QCD Thermodynamics: Confronting the Polyakov-Quark-Meson Model with Lattice QCD. Acta Physica Polonica. Series B, Proceedings Supplement. 2010;3(3):691-700
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