Momentum Analysis in Strong-field Double Ionization

We provide a basis for the laser intensity dependence of the momentum distributions of electrons and ions arising from strong-field non-sequential double ionization (NSDI) at intensities in the range $I=1-6.5 \times 10^{14} W/cm^2$. To do this we use a completely classical method introduced previously \cite{ho-etal05}. Our calculated results reproduce the features of experimental observations at different laser intensities and depend on just two distinct categories of electon trajectories.Comment: 5 pages, 7 figure

Alternative conformal quantum mechanics

We investigate a one dimensional quantum mechanical model, which is invariant under translations and dilations but does not respect the conventional conformal invariance. We describe the possibility of modifying the conventional conformal transformation such that a scale invariant theory is also invariant under this new conformal transformation

R&D Outsourcing Contract with Information Leakage

This paper studies an R&D outsourcing contract between a firm and a contractor, considereing the possibility that in the interim stage, the contractor might sell the innovation to the rival firm. Our result points out that due to the competition in the interim stage, the reward needed to prevent leakage will be pushed up to the extent that a profitable leakage free contract does not exist. This result will also apply to cases considering revenue-sharing schemes and a disclosure punishment for commercial theft. Then, we demonstrate that in a competitive mechanism where the R&D firm hires two contractors together with a relative performance scheme, the disclosure punishment might help and there exists a perfect Bayesian Nash equilibrium where the probability of information leakage is lower and the equilibrium reward is also cheaper than hiring one contractor.R&D outsourcing, Contract, Information leakage, Collusion, Multiple agents

Two-dimensional gases of generalized statistics in a uniform magnetic field

We study the low temperature properties of two-dimensional ideal gases of generalized statistics in a uniform magnetic field. The generalized statistics considered here are the parafermion statistics and the exclusion statistics. Similarity in the behaviours of the parafermion gas of finite order $p$ and the gas with exclusion coefficient $g=1/p$ at very low temperatures is noted. These two systems become exactly equivalent at $T=0$. Qumtum Hall effect with these particles as charge carriers is briefly discussed.Comment: Latex file, 14 pages, 5 figures available on reques

Anapole Dark Matter

We consider dark matter (DM) that interacts with ordinary matter exclusively through an electromagnetic anapole, which is the only allowed electromagnetic form factor for Majorana fermions. We show that unlike DM particles with an electric or magnetic dipole moment, anapole dark matter particles annihilate exclusively into fermions via purely p-wave interactions, while tree-level annihilations into photons are forbidden. We calculate the anapole moment needed to produce a thermal relic abundance in agreement with cosmological observations, and show that it is consistent with current XENON100 detection limits on the DM-nucleus cross-section for all masses, while lying just below the detection threshold for a mass ~ 30-40 GeV.Comment: 7 pages, 5 figures, v3: version to appear in PL

Models for the integer quantum Hall effect: the network model, the Dirac equation, and a tight-binding Hamiltonian

We consider models for the plateau transition in the integer quantum Hall effect. Starting from the network model, we construct a mapping to the Dirac Hamiltonian in two dimensions. In the general case, the Dirac Hamiltonian has randomness in the mass, the scalar potential, and the vector potential. Separately, we show that the network model can also be associated with a nearest neighbour, tight-binding Hamiltonian.Comment: Revtex, 15 pages, 7 figures; submitted to Phys. Rev.

Diabetic foot disease and oedema

Diabetic foot ulcers (DFUs) are common and disabling, giving rise to significant morbidity and mortality as well as worldwide socioeconomic problems. Despite treatment, DFUs readily become chronic wounds and may lead to major lower limb amputations. The pathogenesis of DFUs is complex and the main aetiologies are peripheral neuropathy, ischaemia from peripheral arterial disease and biomechanical abnormalities. Microvascular disease is also a significant problem for people with diabetes and contributes to foot ulceration. Successful management of DFUs consists of debridement, infection control, the use of offloading appliances and revascularisation where necessary. Foot ulcers are usually associated with infection and inflammation which lead to surrounding oedema of the foot. Standard offloading devices such as total contact casts and removable cast walkers do not actively reduce foot oedema. There is promising evidence that active oedema reduction by intermittent pneumatic compression in the diabetic foot improves ulcer healing. The objective of this article is to review the association of foot oedema and DFUs, including the role of appliances which reduce oedema. The information presented is vital to those involved in the management of DFUs. © The Author(s) 2012