We examine wave propagation and the formation of shocks in strongly magnetized plasmas by applying a variational technique and the method of characteristics to the coupled magnetohydrodynamic (MHD) and quantum-electrodynamic (QED) equations of motion. In sufficiently strong magnetic fields such as those found near neutron stars, not only is the plasma extremely relativistic but the effects of Q...

We quantize non-commutative QED canonically in the background field gauge for weak and slowly varying background fields. We determine the complete basis for expansion under such an approximation. As an application, we derive the Wigner function which determines the leading order high temperature behavior of the perturbative amplitudes of non-commutative QED. To leading order, we also give a clo...

The method of NRQED is an adaptation of QED to bound systems. While it is fully equivalent to QED, it enables us to explore the QED bound states systematically as an expansion in the fine structure constant α and velocity (∼ Zα) of the bound electron. I describe how to construct the NRQED Hamiltonian choosing recent works on the α(Zα), α (Zα), α(Zα), α(Zα), and α(Zα) radiative corrections to th...

The role of monopoles in quenched compact QED has been studied by measuring the cluster susceptibility and the order parameter n max /n tot previously introduced by Hands and Wensley in the study of the percolation transition observed in non-compact QED. A correlation between these parameters and the energy (action) at the phase transition has been observed. We conclude that the order parameter...

The emission from an electron in the field of a relativistically strong laser pulse is analyzed. At pulse intensities of J>or=2x10(22) W/cm(2) the emission from counterpropagating electrons is modified by the effects of quantum electrodynamics (QED), as long as the electron energy is sufficiently high: E>or=1 GeV . The radiation force experienced by an electron is for the first time derived fro...

We study almost-forward scattering in the context of usual and non-commutative QED. We study the semi-classical behaviour of particles undergoing this scattering process in the two theories, and show that the shock wave picture, effective in QED fails for NCQED. Further, we show that whereas in QED, there are no leading logarithmic contributions to the amplitude upto sixth order, uncancelled lo...

An effective theory of the excited states positronium is derived and some its consequences are explored. At large physical separation, binding electron positron assumed to be described completely by QED, whereas all short-ranged phenomena, including those within beyond can accounted for with energy-dependent quantum defects. This has at least two practical applications. First, it provides an ac...

In order to develop statistical methods for shapes with a tree-structure, we construct a shape space framework for treelike shapes and study metrics on the shape space. The shape space has singularities, which correspond to topological transitions in the represented trees. We study two closely related metrics, TED and QED. The QED is a quotient euclidean distance arising from the new shape spac...

We consider massless three-dimensional N=1 supersymmetric quantum electrodynamics (QED) with Nf flavours of electrons. Within the dimensional reduction scheme, we compute critical exponents corresponding to both electron and selectron field (parity-even) mass anomalous dimensions at next-to-leading order in 1/Nf expansion an arbitrary covariant gauge. The equality gauge-invariant is found resul...