Consistent Regulation of Infrastructure Businesses: Some Economic Issues

This paper examines some important economic aspects associated with the notion that consistency in the regulation of infrastructure businesses is a desirable feature. It makes two important points. First, it is not easy to measure consistency. In particular, one cannot simply point to different regulatory parameters as evidence of inconsistent regulatory policy. Second, even if one does observe consistency emerging from decisions made by different regulators, it does not necessarily mean that this consistency is desirable. It might be the result, at least partially, of career concerns of regulators.

Electrically charged pulsars

n the present work we investigate one possible variation on the usual electrically neutral pulsars: the inclusion of electric charge. We study the effect of electric charge in pulsars assuming that the charge distribution is proportional to the energy density. All calculations were performed for zero temperature and fixed entropy equations of state

Generalized Born-Infeld-like models for kinks and branes

In this work we deal with a non-canonical scalar field in the two-dimensional spacetime. We search for a generalized model that is twin of the standard model, supporting the same defect structure with the same energy density. We also study the stability of the defect solution under small fluctuations, which is governed by a Sturm-Liouville equation, and show how to make it stable. The model is then modified and used in the five-dimensional spacetime to construct a thick brane that engenders the first order framework and preserves the twinlike behavior, under tensorial fluctuations of the metric in its gravitational sector.Comment: 6 pages; v3, to appear in EP

Particle yields in heavy ion collisions and the influence of strong magnetic fields

It is expected that the magnetic field in the surface of magnetars do not exceed $10^{15}$ G. However, in heavy ion collisions, this value is expected to be much higher. We investigate the effects of a magnetic fields varying from $10^{18}$, to $10^{20}$ G in strange matter (composed of $u$, $d$ and $s$ quarks). We model matter as a free gas of baryons and mesons under the influence of an external magnetic field. We study the effects of such strong fields through a $\chi^2$ fit to some data sets of the STAR experiment. For this purpose we solve the Dirac, Rarita-Schwinger, Klein-Gordon and Proca equations subject to magnetic fields in order to obtain the energy expressions and the degeneracy for spin 1/2, spin 3/2, spin 0 and spin 1 particles, respectively. Our results show that a field of the order of $10^{19}$ G produces an improved fitting to the experimental data as compared to the calculations without magnetic field.Comment: 20 pages, 16 figures, 4 table

Nuclear Matter Properties in Derivative Coupling Models Beyond Mean - Field Approximation

The structure of infinite nuclear matter is studied with two of the Zimanyi - Moszkowski (ZM) models in the framework of a relativistic approximation which takes into account Hartree terms and beyond and is compared with the results which come out of the relativistic Hartree - Fock approach in the linear Walecka model. The simple treatment applied to these models can be used in substitution to the more complicated Dirac - Brueckner - Hartree - Fock method to perform future calculations in finite nuclei.Comment: 11 pages including 1 table, 1 figure (available upon request

The Hold-Out Problem

Suppose a developer wants to buy n adjacent blocks of land that are currently in the possession of n different owners. The value of the blocks of land to the developer is greater than the sum of the individual values of the blocks for each owner. Under complete information about individual valuations, the developer could make a take-it-or-leave-it simultaneous offer to all owners equal to their valuations. The owners would accept the offers, the outcome would be efficient and the developer would get all the surplus. On the other hand, if the owner were to negotiate with the owners sequentially, the final division of the surplus would depend on who would have make the final offer. This individual would end up with the entire surplus and the efficient allocation would be implemented but at the expense of costly delay. Given the possible advantage that arises from being the last to make an offer, players may strategically delay the start of a negotiation. This is the hold-out problem that we examine in this paper. We develop a model in which players decide on the probability that they will go to the negotiating table with the developer. We characterise the full set of equilibria as they correspond to functions of owners valuations, and the developers valuation of subsets of land. Hold out occurs when the developer's valuation of individual blocks is the same as individual owners valuations, or if the valuation of all of the blocks of land by the developer is sufficiently large.