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Complex dynamics in learning complicated games

October 5, 2011 Comments (0)

Game theory is the standard tool used to model strategic interactions in evolutionary biology and social science. Traditional game theory studies the equilibria of simple games. But is traditional game theory applicable if the game is complicated, and if not, what is? We investigate 8ac this question here, defining a complicated game as one with many possible moves, and therefore many possible payoffs conditional on those moves. We investigate two-person games in which the players learn based...

Effects of noise on convergent game learning dynamics

October 5, 2011 Comments (0)

We study stochastic effects on the lagging anchor dynamics, a reinforcement learning algorithm used to lea 757 rn successful strategies in iterated games, which is known to converge to Nash points in the absence of noise. The dynamics is stochastic when players only have limited information about their opponents' strategic propensities. The effects of this noise are studied analytically in the case where it is small but finite, and we show that the statistics and correlation properties of...

Bounding heavy-tailed return distributions to measure model risk

October 5, 2011 Comments (0)

This article makes use of the apparent indifference that the market has been devoting to the developments made on the fundamentals of quantitative finance, to introduce novel insight for better understanding market evolution.We show how these drops and crises emerge as a natural result of local economical p 515 rinciples ruling trades between economical agents and present evidence that heavy-tails of the return distributions are bounded by constraints associated with the topology of agent...

Statistical Physics for Humanities: A Tutorial

October 5, 2011 Comments (0)

The image of physics is connected with simple "mechanical" ac0 deterministic events: that an apple always falls down, that force equals mass times acceleleration. Indeed, applications of such concept to social or historical problems go back two centuries (population growth and stabilisation, by Malthus and by Verhulst) and use "differential equations", as recently revierwed by Vitanov and Ausloos [2011]. However, since even today's computers cannot follow the motion of all air molecules within...

Phase transitions in crowd dynamics of resource allocation

October 5, 2011 Comments (0)

We define and study a class of resources allocation processes where $gN$ agents, by repeatedly visiting $N$ resources, try to converge to optimal configuration where each resource is occupied by at most one agent. The process exhibits a phase transition, as the density $g$ of agents grows, from an absorbing to an active phase. In the latter, even if the number of resources is in principle enough for all agents ($g

The Organization of Strong Links in Complex Networks

October 5, 2011 Comments (0)

A small-world topology characterizes many complex systems including the structural and functional organization 815 of brain networks. The topology allows simultaneously for local and global efficiency in the interaction of the system constituents. However, it ignores the gradations of interactions commonly quantified by the link weight, w. Here, we identify an integrative weight organization for brain, gene, social, and language networks, in which strong links preferentially occur between...

Unveiling the Relationship Between Structure and Dynamics in Complex Networks

October 5, 2011 Comments (0)

Over the last years, a great deal of attention has been focused on complex networked systems, characterized by intricate structure and dynamics. The latter has been often represented in terms of overall statistics (e.g. average and standard deviations) of the time signals. While such approaches have led to many insights, they have failed to take into account that signals at different parts of the system can undergo distinct evolutions, which cannot be properly represented in terms of average...