11,103 research outputs found
A finite difference solution for the cylindrical expansion of a gas cloud into vacuum
Finite difference method for solution of cylindrical expansion of gas cloud into vacuu
Coexistence of Antiferromagnetism and Superconductivity in Electron-doped High-Tc Superconductors
We present magnetotransport evidence for antiferromagnetism in films of the
electron-doped cuprates PrCeCuO. Our results show clear
signature of static antiferromagnetism up to optimal doping x=0.15, with a
quantum phase transition close to x=0.16, and a coexistence of static
antiferromagnetism and superconductivity for 0.12x0.15
Lutheranism, Anti-Judaism, And Bach\u27s St. John Passion: With An Annotated Literal Translation Of The Libretto
Bach\u27s St. John Passion is surely one of the monuments of Western music, yet performances have become inevitably controversial. In large part, this is the result of the combination of powerful, highly emotional music coupled with a text that includes passages from a gospel marked by vehement anti-Judaic sentiments. What did this masterpiece mean in Bach\u27s day, and what does it mean today? Although the bibliographies on Bach and on Judaism have grown enormously since World War II, there has been very little work on the relationships between these two areas. This is hardly surprising writers focusing on issues of anti-Semitism often lack musical training and are, in any event, interested in more pressing social and political issues. Bach scholars, on the other hand, have mostly concentrated on narrowly defined musical topics. And strangely, almost no scholarly attention has been given to the relationships between Lutheranism and Judaism as they affect the St. John Passion. Through a reappraisal of Bach\u27s work and its contexts, Michael Marissen confronts Bach and Judaism directly, providing interpretive commentary that could serve as a basis for more informed and sensitive discussions of this troubling work. Consisting of a long interpretive essay, followed by an annotated literal translation of the libretto, a guide to recorded examples, and a detailed bibliography, this concise text provides the reader with the tools to assess the work on its own terms and in the appropriate contexts. The discussion centers first on the principal messages of the St. John Passion: Jesus\u27 identity, his work, and how this affects the lives of his followers. Marissen goes on to suggest that fostering hostility toward Jews is not the subject or purpose of Bach\u27s setting. For those who would reduce Bach\u27s powerful work to its artistry, and for those listeners who find Bach\u27s music deeply meaningful but may not have considered its attendant religious and cultural issues, as well as for those who assume the work essentially teaches con
Is 0716+714 a superluminal blazar?
We present an analysis of new and old high frequency VLBI data collected
during the last 10 years at 5--22 GHz. For the jet components in the mas-VLBI
jet, two component identifications are possible. One of them with
quasi-stationary components oscillating about their mean positions. Another
identification scheme, which formally gives the better expansion fit, yields
motion with for km s Mpc and .
This model would be in better agreement with the observed rapid IDV and the
expected high Lorentz-factor, deduced from IDV.Comment: 2 pages, 3 figures, appears in: Proceedings of the 6th European VLBI
Network Symposium held on June 25th-28th in Bonn, Germany. Edited by: E. Ros,
R.W. Porcas, A.P. Lobanov, and J.A. Zensu
Blade loss transient dynamics analysis, volume 2. Task 2: Theoretical and analytical development. Task 3: Experimental verification
The component element method was used to develop a transient dynamic analysis computer program which is essentially based on modal synthesis combined with a central, finite difference, numerical integration scheme. The methodology leads to a modular or building-block technique that is amenable to computer programming. To verify the analytical method, turbine engine transient response analysis (TETRA), was applied to two blade-out test vehicles that had been previously instrumented and tested. Comparison of the time dependent test data with those predicted by TETRA led to recommendations for refinement or extension of the analytical method to improve its accuracy and overcome its shortcomings. The development of working equations, their discretization, numerical solution scheme, the modular concept of engine modelling, the program logical structure and some illustrated results are discussed. The blade-loss test vehicles (rig full engine), the type of measured data, and the engine structural model are described
Ground State and Resonances in the Standard Model of Non-relativistic QED
We prove existence of a ground state and resonances in the standard model of
the non-relativistic quantum electro-dynamics (QED). To this end we introduce a
new canonical transformation of QED Hamiltonians and use the spectral
renormalization group technique with a new choice of Banach spaces.Comment: 50 pages change
Second order perturbation theory for embedded eigenvalues
We study second order perturbation theory for embedded eigenvalues of an
abstract class of self-adjoint operators. Using an extension of the Mourre
theory, under assumptions on the regularity of bound states with respect to a
conjugate operator, we prove upper semicontinuity of the point spectrum and
establish the Fermi Golden Rule criterion. Our results apply to massless
Pauli-Fierz Hamiltonians for arbitrary coupling.Comment: 30 pages, 2 figure
Equilibration, generalized equipartition, and diffusion in dynamical Lorentz gases
We prove approach to thermal equilibrium for the fully Hamiltonian dynamics
of a dynamical Lorentz gas, by which we mean an ensemble of particles moving
through a -dimensional array of fixed soft scatterers that each possess an
internal harmonic or anharmonic degree of freedom to which moving particles
locally couple. We establish that the momentum distribution of the moving
particles approaches a Maxwell-Boltzmann distribution at a certain temperature
, provided that they are initially fast and the scatterers are in a
sufficiently energetic but otherwise arbitrary stationary state of their free
dynamics--they need not be in a state of thermal equilibrium. The temperature
to which the particles equilibrate obeys a generalized equipartition
relation, in which the associated thermal energy is equal to
an appropriately defined average of the scatterers' kinetic energy. In the
equilibrated state, particle motion is diffusive
- …