Quantum Group Covariance and the Braided Structure of Deformed Oscillators

The connection between braided Hopf algebra structure and the quantum group covariance of deformed oscillators is constructed explicitly. In this context we provide deformations of the Hopf algebra of functions on SU(1,1). Quantum subgroups and their representations are also discussed.Comment: 12 pages, to be published in JM

Anomalous resonant production of the fourth family up type quarks at the LHC

Considering the present limits on the masses of fourth family quarks from the Tevatron experiments, the fourth family quarks are expected to have mass larger than the top quark. Due to their expected large mass they could have different dynamics than the quarks of three families of the Standard Model. The resonant production of the fourth family up type quark t' has been studied via anomalous production subprocess gq_i-->t' (where q_i=u,c) at the LHC with the center of mass energy 10 TeV and 14 TeV. The signatures of such process are discussed within the SM decay modes. The sensitivity to anomalous coupling \kappa/\Lambda=0.1 TeV^(-1) can be reached at \sqrt{s}=10 TeV and L_int=100 pb^(-1).Comment: 14 pages, 13 figures, 7 table

Foreign Direct Investment and Inequality in Productivity across Countries

Using data for 93 countries for a period from 1970 to 2000, this paper examines the effects of foreign direct investment (FDI) on cross-country differences in productivity. We construct a spatial Gini coefficient of labor productivity across countries, and weighted indices of FDI and gross domestic investment (GDI). We then examine their time series properties to explore the relations of FDI and GDI with productivity. Although we find little evidence of FDI flows – which have increased manifold in last three decades – reducing inequality in productivity for the entire sample, our analysis shows that these three variables are cointegrated for developed, high and middle income developing countries, indicating existence of a long-run equilibrium relationships between FDI, GDI and productivity. FDI seems to reduce inequality in productivity among high and middle income developing countries while it widens productivity gaps among developed countries in the long-run though these effects are statistically significant only for high income developing countries. In middle income developing countries, higher GDI seems to have significant effect in reducing productivity differences. Granger causality tests further suggest that FDI causes productivity differences among petroleum exporting countries. Furthermore, GDI granger causes FDI in high income countries and productivity differences Granger cause FDI into the middle income developing countries.

Evanescent incompressible strips as origin of the observed Hall resistance overshoot

In this work we provide a systematic explanation to the unusual non-monotonic behavior of the Hall resistance observed at two-dimensional electron systems. We use a semi-analytical model based on the interaction theory of the integer quantized Hall effect to investigate the existence of the anomalous, \emph{i.e} overshoot, Hall resistance $R_{H}$. The observation of the overshoot resistance at low magnetic field edge of the plateaus is elucidated by means of overlapping evanescent incompressible strips, formed due to strong magnetic fields and interactions. Utilizing a self-consistent numerical scheme we also show that, if the magnetic field is decreased the $R_{H}$ decreases to its expected value. The effects of the sample width, temperature, disorder strength and magnetic field on the overshoot peaks are investigated in detail. Based on our findings, we predict a controllable procedure to manipulate the maxima of the peaks, which can be tested experimentally. Our model does not depend on specific and intrinsic properties of the material, provided that a single particle gap exists.Comment: A theoretical follow-up paper of arXiv:1007.258