Quark-Gluon Plasma: Present and Future

We review a sample of the experimental results from AGS to SPS and RHIC and their interpretations towards understanding of the Quark-Gluon Plasma. We discuss extrapolations of these results to the upcoming LHC experiments. Finally, we present the plans to probe the QCD critical point with an energy scan at RHIC and FAIR facilities.Comment: Invited talk at the DAE Symposium on Nuclear Physics (December 2007) at Sambalpur University, India. 9 page

On Commodity Prices and Factor Rewards: A Close Look at Sign Patterns

The effect of changes in commodity prices on factor rewards is studied in the multi-commodity, multi-factor case. It is shown that the inverse of the distributive share matrix must satisfy the following restriction: it cannot be anti-symmetric in its sign pattern. This means that one cannot partition the commodities into two groups (I and II) and factors into two groups (A and B), such that all factors in group A benefit (nominally) from all commodity price increases in group I, and simultaneously all factors in group B suffer from all commodity price increases in group II. It turns out that this is also the only sign-pattern restriction imposed by the general nature of the relationship of commodity prices and factor rewards.

On Literacy Rankings

This paper is concerned with the issue of characterizing the situations in which all the literacy indices, consistent with a set of reasonable axioms, would provide the same ranking of societies. It is shown that a theory, analogous to that developed for the Lorenz order in the study of income inequality, can be obtained in the study of literacy, by extending the standard mathematical theory relating gauge functions to convex functions, and the theory of majorization.

Intergenerational Equity and the Forest Management Problem

The paper re-examines the foundations of representation of intertemporal preferences that satisfy intergenerational equity, and provides an axiomatic characterization of those social welfare relations, which are representable by the utilitarian ordering, in ranking consumption sequences which are eventually identical. A maximal point of this ordering is characterized in a standard model of forest management. Maximal paths are shown to converge over time to the forest with the maximum sustained yield, thereby providing a theoretical basis for the tradition in forest management, which has emphasized the goal of maximum sustained yield. Further, it is seen that a maximal point coincides with the optimal point according to the well-known overtaking criterion. This result indicates that the more restrictive overtaking criterion is inessential for a study of forest management under intergenerational equity, and provides a more satisfactory basis for the standard forestry model.

A Characterization of the Turnpike Property of Optimal Paths in the Aggregative Model of Intertemporal Allocation

The paper provides a complete characterization of the turnpike property of optimal paths in the (reduced form) aggregative model of intertemporal allocation. The characterization allows one to identify precisely the bifurcation point between globally stable and cyclical long-run optimal behavior. The complete characterization result is used to evaluate several sufficient conditions for global asymptotic stability of optimal paths that have been proposed in the literature. It is also used to examine sufficient conditions for the emergence of competitive equilibrium cycles in two-sector models.

Shaking during Ion-Atom Collisions

Shaking (shakeup + shakeoff) probabilities accompanying ion-atom collisions are studied using hydrogenic wavefunctions for K-, L-, M- shell electrons in the sudden approximation limit. The role of recoil velocity in the shaking processes is discussed. Further, it is found that the suddenness of collision between projectile and target nuclei plays a major factor in shaking of respective atomic system than the recoil of nuclei.Comment: 10 page

Interacting bosons in generalized zig-zag and railroad-trestle models

We theoretically study the ground-state phase diagram of strongly interacting bosons on a generalized zig-zag ladder model, the rail-road trestle (RRT) model. By means of analytical arguments in the limits of decoupled chains and the case of vanishing fillings as well as extensive DMRG calculations we examine the rich interplay between frustration and interaction for various parameter regimes. We distinguish three different cases, the fully frustrated RRT model where the dispersion relation becomes doubly degenerate and an extensive chiral superfluid regime is found, the anti-symmetric RRT with alternating $\pi$ and $0$ fluxes through the ladder plaquettes and the sawtooth limit, which is closely related to the latter case. We study detailed phase diagrams which include besides different single component superfluids, the chiral superfluid phases, the two component superfluids and different gaped phases, with dimer and a charge-density wave order.Comment: 10 pages, 16 figure