It is one of the most puzzling problems in astrophysics to understand the anomalous resistivity in collisionless magnetic reconnection that is believed extensively to be responsible for the energy release in various eruptive phenomena. The magnetic null point in the reconnect current sheet, acting as a scattering center, can lead to chaotic motions of particles in the current sheet, which is on...

The distinction between chaotic and regular behavior of orbits in galactic models is an important issue and can help our understanding of galactic dynamical evolution. In this paper, we deal with this issue by applying the techniques of the Smaller (and Generalized) ALingment Indices, SALI (and GALI), to extensive samples of orbits obtained by integrating numerically the equations of motion in ...

The global constraints on chaotic dynamics induced by the analyticity of smooth flows are used to dispense with individual periodic orbits and derive infinite families of exact sum rules for several simple dynamical systems. The associated Fredholm determinants are of particularly simple polynomial form. The theory developed suggests an alternative to the conventional periodic orbit theory appr...

9 Black holes and neutron stars are fascinating objects with great potential for testing physical theories in extreme conditions. The gravitational fields near these objects provide an opportunity for tests of General Relativity in the strong-field limit and the properties of matter at the remarkably high densities that exist within neutron stars are unknown. While many of these objects are in ...

A precise analytic model for the relative motion of a group of satellites in slightly elliptic orbits is introduced. With this aim, we describe the relative motion of an object relative to a circular or slightly elliptic reference orbit in the rotating Hill frame via a low-order Hamiltonian, and solve the Hamilton-Jacobi equation. This results in a first-order solution to the relative motion id...

A complete picture of spin polarisation in accelerators and storage rings, either with or without synchrotron radiation, can only be obtained on the basis of evolution equations for combined spin–orbit distributions. See Article I. Moreover, if we are concerned with the effects of radiation, its simulation by classical white noise and damping does not suffice for all situations. For example we ...

Work has been ongoing at the NSLS to improve the orbit stability of the X-Ray Ring by accounting for the thermal motion of the vacuum chamber, which supports the electron beam position monitors (BPMs). In-situ contact measurements of the vacuum chamber motion have been carried out using support stands that have been designed and extensively tested to reduce errors associated with thermal change...

A quantum generalization of the semiclassical theory of Gutzwiller is given. The new formulation leads to systematic orbit-by-orbit inclusion of higher h̄ contributions to the spectral determinant. We apply the theory to billiard systems, and compare the periodic orbit quantization including the first h̄ contribution to the exact quantum mechanical results. Typeset using REVTEX