Slow-roll inflation with a Gauss-Bonnet correction

We consider slow-roll inflation for a single scalar field with an arbitrary potential and an arbitrary nonminimal coupling to the Gauss-Bonnet term. By introducing a combined hierarchy of Hubble and Gauss-Bonnet flow functions, we analytically derive the power spectra of scalar and tensor perturbations. The standard consistency relation between the tensor-to-scalar ratio and the spectral index of tensor perturbations is broken. We apply this formalism to a specific model with a monomial potential and an inverse monomial Gauss-Bonnet coupling and constrain it by the 7-year Wilkinson Microwave Anisotropy Probe data. The Gauss-Bonnet term with a positive (or negative) coupling may lead to a reduction (or enhancement) of the tensor-to-scalar ratio and hence may revive the quartic potential ruled out by recent cosmological data.Comment: 7 pages, 2 figures, RevTeX, references added, published versio

New Method for Numerically Solving the Chemical Potential Dependence of the Dressed Quark Propagator

Based on the rainbow approximation of Dyson-Schwinger equation and the assumption that the inverse dressed quark propagator at finite chemical potential is analytic in the neighborhood of $\mu=0$, a new method for obtaining the dressed quark propagator at finite chemical potential $\mu$ from the one at zero chemical potential is developed. Using this method the dressed quark propagator at finite chemical potential can be obtained directly from the one at zero chemical potential without the necessity of numerically solving the corresponding coupled integral equations by iteration methods. A comparison with previous results is given.Comment: Revtex, 14 pages, 5 figure

Business process re-engineering using a customised mapping model: a case study in a SME

Increasing customer expectations in terms of cost, quality and services, together with competition in global markets has placed a premium on effective internal business processes. Companies are investing to streamline internal workflows, reduce costs and improve efficiency by re-engineering their business processes. Various mapping tools, such as Process Mapping and Value Stream Mapping, have been widely used as the vehicle for leveraging these improvements. However, in isolation any individual tool is often insufficient to achieve the desired results. This article uses a case study approach to investigate a real business process re-engineering (BPR) project in a medium sized manufacturing and service company. Process improvement is carried out using a set of mapping tools that have been selected, simplified and combined for practice. It has been shown that human factors are also crucial to the success of a BPR project. The case study illustrates the success of BPR with real practical examples of what works. Benefits include: increasing stock accuracy from 22% to above 95%; a reduction from about 40 reversed orders per month to zero, order fulfilment time reduced by 50%, and profitability improved 3 times at the end of the project. Non-quantifiable benefits include the elimination of a need for corrective actions, employees are more motivated, and the business stream is flowing smoothly allowing other business processes perform efficiently without disturbance

Critical comments on the paper "Crossing ω=−1\omega=-1 by a single scalar field on a Dvali-Gabadadze-Porrati brane" by H Zhang and Z-H Zhu [Phys.Rev.D75,023510(2007)]

It is demonstrated that the claim in the paper "Crossing $\omega=-1$ by a single scalar field on a Dvali-Gabadadze-Porrati brane" by H Zhang and Z-H Zhu [Phys.Rev.D75,023510(2007)], about a prove that there do not exist scaling solutions in a universe with dust in a Dvali-Gabadadze-Porrati (DGP) braneworld scenario, is incorrect.Comment: 5 pages, 8 eps figure