A procedure to calculate the radiation spectrum emitted by an arbitrarily prepared Dirac wave packet is developed. It is based on the Dirac charge current and classical electrodynamic theory. Apart from giving absolute intensity values, it is exact in terms of relativistic retardation effects and angular dependence. We employ a laser driven free electron to demonstrate the advantages of our met...

In this article we use an electromagnetic Lagrangian constructed so as to include dispersive effects in the description of wave propagating quantum electrodynamic vacuum. This is Lorentz invariant, includes contributions up six powers fields, and involves both fields their first derivatives. Conceptual limitations inherent higher derivative approach are discussed. We consider one-dimensional sp...

We have used a millimeter-wave technique to probe the complex AC conductivity of (TMTSF)$104 in fields to 30 tesla. The fieldinduced-spin-density-wave (FISDW) transitions are clearly seen at low temperatures and low fields, as are the rapid oscillations at higher fields. In addition, we see evidence for a collective pinning mode of the FISDW at high fields.

monkey with vision occluded obtain information about its own motor activities, as would be necessary, for example, when learning new movements? In this regard it is worth considering the possibility of the operation of central feedback mechanisms. Intracentral loops located appropriately could provide a means of monitoring central efferent activity before it has emerged into the periphery. Seve...

33.02 DPS Conference 2005.09.06 We studied several thousand electron density profiles from the Mars Global Surveyor Radio Science experiment. Electron densities in some of these profiles change significantly over vertical distances as short as 1--2 km, often causing localized ``bite-outs''. These ``anomalous'' profiles are preferentially located above crustal magnetic anomalies. Anomalous featu...