The diversity and welfare of older migrants in Europe

This paper sets the scene and provides a conceptual framework for the articles in this special issue. They present the findings of research on European residents who have reached or are on the threshold of old age and whose current circumstances have been strongly influenced by a migration across an international border. Such ‘older migrants’ are scattered throughout Europe and they have especially diverse characteristics. They include some of the most deprived and socially excluded, and some of the most affluent and accomplished, but all to a greater or lesser extent are disadvantaged through an interaction between social policies and their ‘otherness’ by living in a foreign country. Some claim attention through the severity of their unmet health and welfare needs and poor capacity to access advice and treatment, while the affluent groups are of great interest to social gerontology because of their enterprising, developmental and positive approaches to old age. They include among the most innovative of the latest generation of older people, who pursue new combinations of family responsibilities, leisure pursuits and income generation. The paper proposes that the concept ‘human capital’ summarises variations in preparedness for old age, that is, the resources by which people cope with demands for income, roles, treatment, care and support. A typology of the ‘welfare position’ of international migrants in contemporary Europe is presented

Conformal classes of asymptotically flat, static vacuum data

We show that time-reflection symmetric, asymptotically flat, static vacuum data which admit a non-trivial conformal rescaling which leads again to such data must be axi-symmetric and admit a conformal Killing field. Moreover, it is shown that there exists a 3-parameter family of such data.Comment: 23 page

Nonstationary Increments, Scaling Distributions, and Variable Diffusion Processes in Financial Markets

Arguably the most important problem in quantitative finance is to understand the nature of stochastic processes that underlie market dynamics. One aspect of the solution to this problem involves determining characteristics of the distribution of fluctuations in returns. Empirical studies conducted over the last decade have reported that they arenon-Gaussian, scale in time, and have power-law(or fat) tails. However, because they use sliding interval methods of analysis, these studies implicitly assume that the underlying process has stationary increments. We explicitly show that this assumption is not valid for the Euro-Dollar exchange rate between 1999-2004. In addition, we find that fluctuations in returns of the exchange rate are uncorrelated and scale as power-laws for certain time intervals during each day. This behavior is consistent with a diffusive process with a diffusion coefficient that depends both on the time and the price change. Within scaling regions, we find that sliding interval methods can generate fat-tailed distributions as an artifact, and that the type of scaling reported in many previous studies does not exist.Comment: 12 pages, 4 figure

Double-Well Potential : The WKB Approximation with Phase Loss and Anharmonicity Effect

We derive a general WKB energy splitting formula in a double-well potential by incorporating both phase loss and anharmonicity effect in the usual WKB approximation. A bare application of the phase loss approach to the usual WKB method gives better results only for large separation between two potential minima. In the range of substantial tunneling, however, the phase loss approach with anharmonicity effect considered leads to a great improvement on the accuracy of the WKB approximation.Comment: 14 pages, revtex, 1 figure, will appear at Phys. Rev.

The near-synchronous polar V1432 Aql (RX J1940.1-1025): Accretion geometry and synchronization time scale

The magnetic Cataclysmic Variable (mCV) V1432 Aql (RX 1940.1-1025) belongs to the four-member subclass of near-synchronous polars with a slight non-synchronism (<2 %) between the spin period of the white dwarf and the binary period. In these systems the accretion geometry changes periodically with phase of the beat cycle. We present the application of a dipole accretion model for near-synchronous systems developed by Geckeler & Staubert (1997a) to extended optical and X-ray data. We detect a significant secular change of the white dwarf spin period in V1432 Aql of dP_spin/dt = -5.4 (+3.7/-3.2) 10-9 s/s from the optical data set alone. This corresponds to a synchronization time scale tau_sync = 199 (+441/-75) yr, comparable to the time scale of 170 yr for V1500 Cyg. The synchronization time scale in V1432 Aql is in excellent agreement with the theoretical prediction from the dominating magnetic torque in near-synchronous systems. We also present period analyses of optical CCD photometry and RXTE X-ray data, which argue against the existence of a 4000 s period and an interpretation of V1432 Aql as an intermediate polar. The dipole accretion model also allows to constrain the relevant parameters of the accretion geometry in this system: the optical data allow an estimate of the dimensionless parameter (R_t0'/R_wd)1/2 sin(beta) = 3.6 (+2.7/-1.1), with a lower limit for the threading radius of R_t0' > 10 R_wd (68% confidence).Comment: 12 pages, 10 figures, 6 tables accepted by A&

On a choice of the Bondi radial coordinate and news function for the axisymmetric two-body problem

In the Bondi formulation of the axisymmetric vacuum Einstein equations, we argue that the ``surface area'' coordinate condition determining the ``radial'' coordinate can be considered as part of the initial data and should be chosen in a way that gives information about the physical problem whose solution is sought. For the two-body problem, we choose this coordinate by imposing a condition that allows it to be interpreted, near infinity, as the (inverse of the) Newtonian potential. In this way, two quantities that specify the problem -- the separation of the two particles and their mass ratio -- enter the equations from the very beginning. The asymptotic solution (near infinity) is obtained and a natural identification of the Bondi "news function" in terms of the source parameters is suggested, leading to an expression for the radiated energy that differs from the standard quadrupole formula but agrees with recent non-linear calculations. When the free function of time describing the separation of the two particles is chosen so as to make the new expression agree with the classical result, closed-form analytic expressions are obtained, the resulting metric approaching the Schwarzschild solution with time. As all physical quantities are defined with respect to the flat metric at infinity, the physical interpretation of this solution depends strongly on how these definitions are extended to the near-zone and, in particular, how the "time" function in the near-zone is related to Bondi's null coordinate.Comment: 13 pages, LaTeX, submitted to Classical and Quantum Gravity; v2 corrected a few typos and added some comments; v3 expanded discussion and added references -- Rejected by CQG; v4: 8 pages revtex4 2 column, extensively revised, submitted to Phys Rev D; v5: 21 pages revtex4 preprint; further discussion of physical interpretation; v6: 21 pages revtex4 preprint -- final version to appear in Phys. Rev. D (2006

Colloids dragged through a polymer solution: experiment, theory and simulation

We present micro-rheological measurments of the drag force on colloids pulled through a solution of lambda-DNA (used here as a monodisperse model polymer) with an optical tweezer. The experiments show a violation of the Stokes-Einstein relation based on the independently measured viscosity of the DNA solution: the drag force is larger than expected. We attribute this to the accumulation of DNA infront of the colloid and the reduced DNA density behind the colloid. This hypothesis is corroborated by a simple drift-diffusion model for the DNA molecules, which reproduces the experimental data surprisingly well, as well as by corresponding Brownian dynamics simulations.Comment: 9 pages, 13 figures, 3 table