Marcelo del Castillo-Mussot

Continuous opinion model in small-world directed networks

In the compromise model of continuous opinions proposed by Deffuant et al., the states of two agents in a network can start to converge if they are neighbors and if their opinions are sufficiently close to each other, below a given threshold of tolerance ϵ. In directed networks, if agent i is a neighbor of agent j,j need not be a neighbor of i. In Watts–Strogatz networks we performed simulations to find the averaged number of final opinions 〈F〉 and their distribution as a function of ϵ and of the network structural disorder. In directed networks 〈F〉 exhibits a rich structure, being larger than in undirected networks for higher values of ϵ, and smaller for lower values of ϵ.

Move-by-Move Dynamics of the Advantage in Chess Matches Reveals Population-Level Learning of the Game

The complexity of chess matches has attracted broad interest since its invention. This complexity and the availability of large number of recorded matches make chess an ideal model systems for the study of population-level learning of a complex system. We systematically investigate the move-by-move dynamics of the white player’s advantage from over seventy thousand high level chess matches spanning over 150 years. We find that the average advantage of the white player is positive and that it has been increasing over time. Currently, the average advantage of the white player is 0.17 pawns but it is exponentially approaching a value of 0.23 pawns with a characteristic time scale of 67 years. We also study the diffusion of the move dependence of the white player’s advantage and find that it is non-Gaussian, has long-ranged anti-correlations and that after an initial period with no diffusion it becomes super-diffusive. We find that the duration of the non-diffusive period, corresponding to the opening stage of a match, is increasing in length and exponentially approaching a value of 15.6 moves with a characteristic time scale of 130 years. We interpret these two trends as a resulting from learning of the features of the game. Additionally, we find that the exponent characterizing the super-diffusive regime is increasing toward a value of 1.9, close to the ballistic regime. We suggest that this trend is due to the increased broadening of the range of abilities of chess players participating in major tournaments.

Heider balance, asymmetric ties, and gender segregation

To remove a cognitive dissonance in interpersonal relations, people tend to divide their acquaintances into friendly and hostile parts, both groups internally friendly and mutually hostile. This process is modeled as an evolution toward the Heider balance. A set of differential equations have been proposed and validated (Kulakowski et al., 2005) to model the Heider dynamics of this social and psychological process. Here we generalize the model by including the initial asymmetry of the interpersonal relations and the direct reciprocity effect which removes this asymmetry. Our model is applied to the data on enmity and friendship in 37 school classes and 4 groups of teachers in Mexico. For each class, a stable balanced partition is obtained into two groups. The gender structure of the groups reveals stronger gender segregation in younger classes, i.e. of age below 12 years, a fact consistent with other general empirical results.

Stark effect in a wedge-shaped quantum box

Abstract The effect of an external applied electric field on the electronic ground-state energy of a quantum box with a geometry defined by a wedge is studied by carrying out a variational calculation. This geometry could be used as an approximation for a tip of a cantilever of an atomic force microscope. We study theoretically the Stark effect as function of the parameters of the wedge: its diameter, angular aperture and thickness; as well as function of the intensity of the external electric field applied along the axis of the wedge in both directions; pushing the carrier towards the wider or the narrower parts. A confining electronic effect, which is sharper as the wedge dimensions are smaller, is clearly observed for the first case. Besides, the sign of the Stark shift changes when the angular aperture is changed from small angles to angles θ > π . For the opposite field, the electronic confinement for large diameters is very small and it is also observed that the Stark shift is almost independent with respect to the angular aperture.

Stark effect on a geometry defined by a cake's slice

By using a variational calculation, we study the effect of an external applied electric field on the ground state of electrons confined in a quantum box with a geometry defined by a slice of a cake. This geometry is a first approximation for a tip of a cantilever of an atomic force microscope. By modeling the tip with the slice, we calculate the electronic ground-state energy as a function of the slices diameter, its angular aperture, its thickness and the intensity of the external electric field applied along the slice. For the applied field pointing to the wider part of the slice, a confining electronic effect in the opposite side is clearly observed. This effect is sharper as the angular slices aperture is smaller and there is more radial space to manifest itself.

Impact of Global Energy Resources Based on Energy Return on their Investment ( EROI ) Parameters

Human development has been based on the use of the energy resources, especially those of fossil origin (oil, gas, coal, etc.), which are not infinite and damage ecosystems; it is of paramount importance to make a transition to other alternative sources of energy. We compare and discuss many global sources of energy and their impact, based on the useful parameter called energy returned on energy invested or energy return on investment ( EROI ). In the long run we could expect renewed emphasis on enhanced (stimulated or hot dry rock) geothermal energy sources due to technological advances in deep drilling and the availability of this kind of energy 365 days per year and 24 hours of a day.

Global Capitalism and “North-South” Unevenness: In Light of Ranking, Statistical Correlations, and Profits from the Forbes’ Worldwide List of 2000 Top Firms

AbstractWhile a ‘north-south divide’ in world capitalism has been pointed to for many years, in this article we examine how this unevenness continues in today’s epoch of capitalist globalization. To examine this phenomenon, we analyze a recent Forbes Magazine annual ranking of the leading 2000 companies in the world (G2000), by grouping or ‘boxing’ these companies by their 62 domiciles to calculate aggregated sales, profits, assets and market value and correlating these quantities with the GDP of the corresponding domicile. This is an approximation to reality, since the variety of transnational capital and associated global processes make it nowadays problematic to assign national labels to capital. Regardless of where the whole business circuit takes place, we found that the GDP of each country is directly proportional, more or less, to the economic strength of all G2000 top firms based or registered in that country. These proportionalities tend to hover around a certain level globally, yet the correlation is lower for the ‘global south’ (as some describe it). We can also identify important regional variations of ratios such as profits/sales. Other ratios could also be easily calculated from our results. Together these findings help lead to a more nuanced understanding of transnational corporations (TNCs), but also suggest more basically, for instance, that the ‘global north’ remains to some degree more penetrated by TNCs (of the G2000).

Global Capitalism and the Neoliberal Privatization of Energy Reserves: A Mexico Case Study

In 2013 state officials operating through the three federal government branches of Mexico mutilated the country’s constitution, privatizing upwards of seventy-five percent of the country’s hydrocarbon reserves. This article suggests that this neoliberal strategy, carried out by transnationally oriented elites operating through state apparatuses in Mexico (and promoted by officials in Washington and within the International Financial Institutions), is meant to benefit transnational capital. Such drastic change to Mexico’s legal order, we argue, in fact violated the country’s constitution and symbolized a break with the country’s earlier model of development. The federal government’s anti-constitutional behavior, specifically its violation of Article 136 of the constitution, provides a legal basis for dismissing top officials from their posts and moving toward a constitutional assembly.

Internal Violent Conflicts and Overt War among National States

We focus on geopolitical tensions, possibilities of internal violent conflicts or overt war among national-states. First, we examine the most important concepts and practices of the neoliberal globalization. The current world situation seems to indicate that neoliberalism is not a theory, a class strategy designed to redistribute wealth upward toward an increasingly narrow fraction of people, despite national contradictions. We review sources of international tensions and some important data of transnational corporations in the North and South. Historical experiences show that crisis can produce different kinds of changes and distinct political responses in societies, such as internal violent conflicts or overt war among national-states. Some of these conflicts can be analyzed by employing two frameworks; national-states framework and global class relations. We argue that in a highly globalized world, the existence of overt war among strong nation-states could seriously damage the globalist bloc transnational commanding class, whereas internal violent conflicts can easily appear almost everywhere as a natural consequence of social and economic inequalities. In order to counterweight the crisis and fascist movements we propose alliances among the dominated classes and other dominated groups.