Acceleration and Cyclotron Radiation, Induced by Gravitational Waves

The equations which determine the response of a charged particle moving in a magnetic field to an incident gravitational wave(GW) are derived in the linearized approximation to general relativity. We briefly discuss several astrophysical applications of the derived formulae taking into account the resonance between the wave and the particle's motion which occurs at $\omega_g=2\Omega$, whenever the GW is parallel to the constant magnetic field. In the case where the GW is perpendicular to the constant magnetic field, magnetic resonances appear at $\omega_g=\Omega$ and $\omega_g=2\Omega$. Such resonant mechanism may be useful to build models of GW driven cyclotron emitters.Comment: 16 pages, 1 figure, accepted for publication in Astronomy & Astrophysic

The Solutions of Affine and Conformal Affine Toda Field Theories

We give new formulations of the solutions of the field equations of the affine Toda and conformal affine Toda theories on a cylinder and two-dimensional Minkowski space-time. These solutions are parameterised in terms of initial data and the resulting covariant phase spaces are diffeomorphic to the Hamiltonian ones. We derive the fundamental Poisson brackets of the parameters of the solutions and give the general static solutions for the affine theory.Comment: 11pp, phyzz

Gravitational waves interacting with a spinning charged particle in the presence of a uniform magnetic field

The equations which determine the response of a spinning charged particle moving in a uniform magnetic field to an incident gravitational wave are derived in the linearized approximation to general relativity. We verify that 1) the components of the 4-momentum, 4-velocity and the components of the spinning tensor, both electric and magnetic moments, exhibit resonances and 2) the co-existence of the uniform magnetic field and the GW are responsible for the resonances appearing in our equations. In the absence of the GW, the magnetic field and the components of the spin tensor decouple and the magnetic resonances disappear.Comment: 19 pages, accepted for publication in Gen. Rel. Gra

Differences in Physical Activity and Built Environment Perceptions Between Younger and Older Adults Living in the Same Rural

This study examined associations between perceptions and physical activity of younger and older adults residing in the same rural/small town community. Thirty-two adults completed interviews about their community and their physical activity. Both groups perceived their neighborhood as pleasant and safe to be active. Fewer older adults perceived their neighborhood as having sidewalks. Younger adults reported being more vigorously active and they were more often utilizing private membership clubs for physical activity. Older adults utilized more public recreational facilities. These results suggest that higher perceived quality of the neighborhood built environment can enhance participation in moderate exercise in older adults

String Thermalization in Static Spacetimes

We study the evolution, the transverse spreading and the subsequent thermalization of string states in the Weyl static axisymmetric spacetime. This possesses a singular event horizon on the symmetry axis and a naked singularity along the other directions. The branching diffusion process of string bits approaching the singular event horizon provides the notion of temperature that is calculated for this process. We find that the solution of the Fokker-Planck equation in the phase space of the transverse variables of the string, can be factored as a product of two thermal distributions, provided that the classical conjugate variables satisfy the uncertainty principle. We comment on the possible physical significance of this result.Comment: 16 pages, no figures, Late