Spontaneous Breaking of Translational Invariance in One-Dimensional Stationary States on a Ring

We consider a model in which positive and negative particles diffuse in an asymmetric, CP-invariant way on a ring. The positive particles hop clockwise, the negative counterclockwise and oppositely-charged adjacent particles may swap positions. Monte-Carlo simulations and analytic calculations suggest that the model has three phases; a "pure" phase in which one has three pinned blocks of only positive, negative particles and vacancies, and in which translational invariance is spontaneously broken, a "mixed" phase with a non-vanishing current in which the three blocks are positive, negative and neutral, and a disordered phase without blocks.Comment: 7 pages, LaTeX, needs epsf.st

Yang-Lee Theory for a Nonequilibrium Phase Transition

To analyze phase transitions in a nonequilibrium system we study its grand canonical partition function as a function of complex fugacity. Real and positive roots of the partition function mark phase transitions. This behavior, first found by Yang and Lee under general conditions for equilibrium systems, can also be applied to nonequilibrium phase transitions. We consider a one-dimensional diffusion model with periodic boundary conditions. Depending on the diffusion rates, we find real and positive roots and can distinguish two regions of analyticity, which can identified with two different phases. In a region of the parameter space both of these phases coexist. The condensation point can be computed with high accuracy.Comment: 4 pages, accepted for publication in Phys.Rev.Let

FDI and Domestic Investment: An Industry-Level View

Previous empirical work on the link between domestic and foreign investment provides mixed results which partly depend on the level of aggregation of the data. We argue that the aggregated home country implications of foreign direct investment (FDI) cannot be gauged using firm-level data. Aggregated data, in turn, miss channels through which domestic and foreign activities interact. Instead, industry-level data provide useful information on the link between domestic and foreign investment. We theoretically show that the effects of FDI on the domestic capital stock depend on the structure of industries and the relative importance of domestic and multinational firms. Our model allows distinguishing intra-sector competition from inter-sector linkage effects. We test the model using data on German FDI. Using panel cointegration methods, we find evidence for a positive long-run impact of FDI on the domestic capital stock and on the stock of inward FDI. Effects of FDI on the domestic capital stock are driven mainly by intrasector effects. For inward FDI, inter-sector linkages matter as well

Are classically singular spacetimes quantum mechanically singular as well?

Are the classical singularities of general relativistic spacetimes, normally defined by the incompleteness of classical particle paths, still singular if quantum mechanical particles are used instead? This is the question we will attempt to answer for particles obeying the quantum mechanical wave equations for scalar, null vector and spinor particles. The analysis will be restricted to certain static general relativistic spacetimes that classically contain the mildest true classical singularities, quasiregular singularities.Comment: 3 pages, no figures, submitted to the Proceedings of the Tenth Marcel Grossmann Meeting on General Relativity, Rio de Janeiro, July 20-26, 200

The energies and residues of the nucleon resonances N(1535) and N(1650)

We extract pole positions for the N(1535) and N(1650) resonances using two different models. The positions are determined from fits to different subsets of the existing $\pi N\to\pi N$, $\pi N\to\eta N$ and $\gamma p\to\eta p$ data and found to be 1515(10)--i85(15)MeV and 1660(10)--i65(10)MeV, when the data is described in terms of two poles. Sensitivity to the choice of fitted data is explored. The corresponding $\pi \pi$ and $\eta \eta$ residues of these poles are also extracted.Comment: 9 page

Experimental verification of the Heisenberg uncertainty principle for hot fullerene molecules

The Heisenberg uncertainty principle for material objects is an essential corner stone of quantum mechanics and clearly visualizes the wave nature of matter. Here we report a demonstration of the Heisenberg uncertainty principle for the most massive, complex and hottest single object so far, the fullerene molecule C70 at a temperature of 900 K. We find a good quantitative agreement with the theoretical expectation: dx * dp = h, where dx is the width of the restricting slit, dp is the momentum transfer required to deflect the fullerene to the first interference minimum and h is Planck's quantum of action.Comment: 4 pages, 4 figure

Extraction of the πNN\pi NN coupling constant from NN scattering data

We reexamine Chew's method for extracting the $\pi NN$ coupling constant from np differential cross section measurements. Values for this coupling are extracted below 350 MeV, in the potential model region, and up to 1 GeV. The analyses to 1~GeV have utilized 55 data sets. We compare these results to those obtained via $\chi^2$ mapping techniques. We find that these two methods give consistent results which are in agreement with previous Nijmegen determinations.Comment: 12 pages of text plus 2 figures. Revtex file and postscript figures available via anonymous FTP at ftp://clsaid.phys.vt.edu/pub/n

FDI and Domestic Investment: An Industry-Level View

Previous empirical work on the link between domestic and foreign investment provides mixed results which partly depend on the level of aggregation of the data. We argue that the aggregated home country implications of foreign direct investment (FDI) cannot be gauged using firm-level data. Aggregated data, in turn, miss channels through which domestic and foreign activities interact. Instead, industry-level data provide useful information on the link between domestic and foreign investment. We theoretically show that the effects of FDI on the domestic capital stock depend on the structure of industries and the relative importance of domestic and multinational firms. Our model allows distinguishing intra-sector competition from inter-sector linkage effects. We test the model using data on German FDI. Using panel cointegration methods, we find evidence for a positive long-run impact of FDI on the domestic capital stock and on the stock of inward FDI. Effects of FDI on the domestic capital stock are driven mainly by intrasector effects. For inward FDI, inter-sector linkages matter as well.foreign direct investment; domestic capital stock

Barriers to exporting: Firm-Level Evidence from Germany

Recent literature stresses the importance of low productivity as a barrier to the international expansion of firms. But financial frictions or adverse employment conditions at home could matter as well. In this paper, we present new empirical evidence on the importance of these factors. We use a detailed micro-level dataset of German firms which simultaneously provides information on exports, financial frictions, and labor market conditions. Our paper has three main findings. First, in line with earlier literature, we find a positive impact of size and productivity on firms’ export activities. Second, financial constraints affect the entry into foreign market (extensive margin) more than the volume of exports (intensive margin). Third, labor market conditions have a mixed impact on export activities. The most consistent finding is that firms covered by collective bargaining agreements are less likely to be exporters and export less.multinational firms, exports, firm heterogeneity, productivity