'The Voracity Effect' and Climate Change: The Impact of Clean Technologies

In the absence of a successful international cooperative agreement over the control of emissions there is a growing interest in the role that clean technologies may play to alleviate the climate change problem. Within a non-cooperative transboundary pollution game, we investigate, analytically and within a numerical example based on empirical evidence, the impact of the adoption of a cleaner technology (i.e., a decrease in the emission to output ratio). We show that countries may respond by increasing their emissions resulting in an increase in the stock of pollution that may be detrimental to welfare. This possibility is shown to arise for a signi cant and empirically relevant range of parameters. It is when the damage and/or the initial stock of pollution are relatively large and when the natural rate of decay of pollution is relatively small that the perverse e¤ect of clean technologies is strongest. Cooperation over the control of emissions is necessary to ensure that the development of cleaner technologies does not exacerbate the free riding behavior that is at the origin of the climate change problem.transboundary pollution;renewable resource;climate change;clean technolo- gies;differential games

Collusion Inducing Taxation of a Polluting Oligopoly

We show that an environmental regulation such as a tax on pollution can act as a collusive device and induce stable cartelization in an oligopolistic polluting industry. We consider a dynamic game where pollution is allowed to accumulate into a stock over time and a cartel that includes all the firms in the industry. We show that a tax on pollution emissions can make it unprofitable for any firm to leave the cartel. Moreover the cartel formation can diminish the welfare gain from environmental regulation. We provide an example where social welfare under environmental regulation and collusion of firms is below social welfare under a laisser-faire policy.pollution tax;oligopoly;cartel formation;coalition formation;differential game

Welfare Effect of Mergers and Trade Liberalization

In a two-country model where firms behave à la Cournot, we show that marginal and non-marginal trade liberalization have different effects on the social desirability of horizontal mergers. Marginal tariff reductions increase (decrease) the desirability of merger at sufficiently low (high) tariff levels. In the neighborhood of free trade, for sufficiently low cost savings from merger, trade liberalization increases the desirability of merger whilst decreasing the profitability, implying that mergers should be actively encouraged by competition authorities. Furthermore, we identify ranges of tariff levels for which, if trade liberalization increases (decreases) the desirability of merger, it necessarily increases (decreases) its profitability.

Dust interferometers in plasmas

An interferometric imaging technique has been proposed to instantly measure the diameter of individual spherical dust particles suspended in a gas discharge plasma. The technique is based on the defocused image analysis of both spherical particles and their binary agglomerates. Above a critical diameter, the defocused images of spherical particles contain stationary interference fringe patterns and the fringe number increases with particle diameters. Below this critical diameter, the particle size has been measured using the rotational interference fringe patterns which appear only on the defocused images of binary agglomerates. In this case, a lower cut-off limit of particle diameter has been predicted, below which no such rotational fringe patterns are observed for the binary agglomerates. The method can be useful as a diagnostics for complex plasma experiments on earth as well as under microgravity condition

Quasi-two-dimensional complex plasma containing spherical particles and their binary agglomerates

A new type of quasi-two-dimensional complex plasma system was observed which consisted of monodisperse microspheres and their binary agglomerations (dimers). The particles and their dimers levitated in a plasma sheath at slightly different heights and formed two distinct sublayers. The sys- tem did not crystallize and may be characterized as disordered solid. The dimers were identified based on their characteristic appearance in defocused images, i.e., rotating interference fringe pat- terns. The in-plane and inter-plane particle separations exhibit nonmonotonic dependence on the discharge pressure which agrees well with theoretical predictions

Adaptation Effectiveness and Free-Riding Incentives in International Environmental Agreements

While an international agreement over the reduction of greenhouse gases (GHGs) emissions proves to be elusive, there is a large and growing support for investment in developing more effective technologies to adapt to climate change. We show that an increase in effectiveness of adaptation will diminish the incentive of individual countries to free-ride on a global agreement over emissions. Moreover, we show that this positive effect of an increase in adaptation's effectiveness can also be accompanied by an increase in the gains from global cooperation over GHGs emissions.adaptation;climate change;international environmental agreements;transboundary pollution

Centrality dependence of elliptic flow and QGP viscosity

In the Israel-Stewart's theory of second order hydrodynamics, we have analysed the recent PHENIX data on charged particles elliptic flow in Au+Au collisions. PHENIX data demand more viscous fluid in peripheral collisions than in central collisions. Over a broad range of collision centrality (0-10%- 50-60%), viscosity to entropy ratio ($\eta/s$) varies between 0-0.17.Comment: Final version to be publiashed in J. Phys. G. 8 pages, 6 figures and 3 table

Equilibrium glassy phase in a polydisperse hard sphere system

The phase diagram of a polydisperse hard sphere system is examined by numerical minimization of a discretized form of the Ramakrishnan-Yussouff free energy functional. Crystalline and glassy local minima of the free energy are located and the phase diagram in the density-polydispersity plane is mapped out by comparing the free energies of different local minima. The crystalline phase disappears and the glass becomes the equilibrium phase beyond a "terminal" value of the polydispersity. A crystal to glass transition is also observed as the density is increased at high polydispersity. The phase diagram obtained in our study is qualitatively similar to that of hard spheres in a quenched random potential.Comment: 4 pages, 4 figure