The emergence of a self-catalysing structure in abstract origin-of-life models

We formalize a class of abstract and simple biochemical models that have been proposed for understanding the origin of life. We then analyse conditions under which “life-like” substructures will tend to arise in such models.     

Mathematical models for explaining the emergence of specialization in performing tasks

In an evolving community consisting of many individuals, it is often the case that the individuals tend, over time, to become more specialized in performing the tasks necessary for survival and growth of the community as a whole. The contribution in this work is a collection of linear and nonlinear mathematical models that provide insights as to when and why functional specialization emerges in general, rather than specific, settings. The results from these models, which are based on an evolutionary approach, apply to communities in which individuals allocate their time in the best interest of the community as a whole. © 2004 Wiley Periodicals, Inc. Complexity 10:37–48, 2004     

The emergence of time

Classically, one could imagine a completely static space, thus without time. As is known, this picture is unconceivable in quantum physics due to vacuum fluctuations. The fundamental difference between the two frameworks is that classical physics is commutative (simultaneous observables) while quantum physics is intrinsically noncommutative (Heisenberg uncertainty relations). In this sense, we may say that time is generated by noncommutativity; if this statement is correct, we should be able to derive time out of a noncommutative space. We know that a von Neumann algebra is a noncommutative space. About 50 years ago the Tomita–Takesaki modular theory revealed an intrinsic evolution associated with any given (faithful, normal) state of a von Neumann algebra, so a noncommutative space is intrinsically dynamical. This evolution is characterised by the Kubo–Martin–Schwinger thermal equilibrium condition in quantum statistical mechanics (Haag, Hugenholtz, Winnink), thus modular time is related to temperature. Indeed, positivity of temperature fixes a quantum-thermodynamical arrow of time. We shall sketch some aspects of our recent work extending the modular evolution to a quantum operation (completely positive map) level and how this gives a mathematically rigorous understanding of entropy bounds in physics and information theory. A key point is the relation with Jones’ index of subfactors. In the last part, we outline further recent entropy computations in relativistic quantum field theory models by operator algebraic methods, that can be read also within classical information theory. The information contained in a classical wave packet is defined by the modular theory of standard subspaces and related to the quantum null energy inequality.     

The emergence of computational sociology

The world of science has undergone a major transformation by virtue of technological innovations in computing and information proessing. Sociology is one site in which this change is being played out. Our basic aim is to set out a revised image of any modern science, within which we can conceptualize and discuss the role of a newly emergent subfield we term computational sociology. Specifically, we expand the familiar two‐component model of a science, featuring a theoretical and an empirical side, to include a computational component. We show how the three components interrelate in a triangular system in which empirical data analysis, theoretical explanation and computer simulation link the three components. We close our paper with a brief discussion of how one new development in computation relates to concepts of sociology, an instance of the hybrid character of computational sociology.     

The emergence of risk aversion

Economic decision making under uncertainty is universally characterized by aversion to risk. One of the most basic concepts in economic theory, risk aversion is usually explained by the concavity of the utility function, which, in turn, is based on a person's satiability for wealth. I use genetic algorithms to show that risk aversion, and some related consequences, emerge naturally as a result of evolutionary pressures. In analogy to the well-known hillclimbing metaphor, it is helpful in this context to characterize optimizing under uncertainty as “surfing in a fitness seascape.” © 1997 John Wiley & Sons, Inc.     

The emergence of local norms in networks

We develop an explanation of the emergence of local norms and the associated phenomenon of geographical variation in behavior. Individuals are assumed to interact locally with neighbors in an environment with a network externality. Although many patterns of behavior are possible, the dispersed interactive choices of agents are shown to select behavior that is locally uniform but globally diverse. The range of applications of the theory includes regional variation in the practice of medicine, technology choice, and corruption. The framework is also useful for further developing our understanding of important phenomena like lock‐in, critical thresholds, and contagion. © 2006 Wiley Periodicals, Inc. Complexity 11: 65–83, 2006     

The emergence of profit in life insurance

Traditionally, the mortality tables used in life insurance have margins of safety built into them, and profit can, therefore, be expected to emerge over the life of a portfolio of business. In this paper life insurance policies are modelled by means of time-inhomogeneous Markov chains, and the paper examines some of the stochastic properties of the gains attributable to the various forces of transition. A reversionary annuity serves as an illustrating example.     

The outbreak of cooperation

We study the ongoing collective action problem among intentional agents whose choices depend not only on the past but also on their expectations as to how their actions will affect those of others. In this model agents act on the basis of imperfect information. We show that under these conditions the onset of overall cooperation can take place in a sudden and unexpected way. Likewise, defection can appear out of nowhere in very large, previously cooperating groups. These outbreaks mark the end of long transient states in which defection or cooperation persists in groups that cannot sustain it indefinitely.     

The emergence of deontological codes in public administration

We study a model of the evolutionary selection of social standards of behavior in a large public organization, in terms of the propensity to bribery of the organization's rent-seeking officers. We examine several scenarios, allowing for the existence of various types of anti-corruption sanctioning mechanisms, for the role of pro-social, interiorized value systems, for the impact of informational costs on the viability of "informationally sophisticated" players. The conditions under which corruption is eventually eliminated or at least kept under control in the various scenarios are derived and discussed.     

The evolution of cooperation in spatial groups

Much of human cooperation remains an evolutionary riddle. There is evidence that individuals are often organized into groups in many social situations. Inspired by this observation, we propose a simple model of evolutionary public goods games in which individuals are organized into networked groups. Here, nodes in the network represent groups; the edges, connecting the nodes, refer to the interactions between the groups. Individuals establish public goods games with partners in the same group and migrate among neighboring groups depending on their payoffs and expectations. We show that the paradigmatic public goods social dilemma can be resolved and high cooperation levels are attained in structured groups, even in relatively harsh conditions for cooperation. Further, by means of numerical simulations and mean-field analysis, we arrive at the result: larger average group size and milder cooperation environment would lead to lower cooperation level but higher average payoffs of the entire population. Altogether, these results emphasize that our understanding of cooperation can be enhanced by investigations of how spatial groups of individuals affect the evolution dynamics, which might help in explaining the emergence and evolution of cooperation.     

The emergence of the Planck scale

In this paper, we first observe some interesting parallels between Planck scale considerations and elementary particle Compton wavelength scale considerations, particularly in the context of Wheeler's space-time foam and a space-time arising out of a stochastic random heap of elementary particles discussed in previous papers. These parallels lead to a semi-qualitative picture which shows how the short-lived Planck scale arises from the Compton wavelength considerations. Finally all this is quantified.     

The emergence of groups in the evolution of friendship networks

Friendship networks usually show a certain degree of segmentation: subgroups of friends. The explanation of the emergence of such groups from initially dyadic pair friendships is a difficult but important problem. In this paper we attempt to provide a first contribution to the explanation of subgroup formation in friendship networks by using the LS set as a definition for a friendship group. We construct a dynamic individual oriented model of friendship formation and provide preliminary simulation results that give an idea of how to continue the process of explaining group formation.     

Anchorage strength models for end-debonding predictions in RC beams strengthened with FRP composites

The increase in the flexural capacity of RC beams obtained by externally bonding FRP composites to their tension side is often limited by the premature and brittle debonding of the external reinforcement. An in-depth understanding of this complex failure mechanism, however, has not yet been achieved. With specific regard to end-debonding failure modes, extensive experimental observations reported in the literature highlight the important distinction, often neglected in strength models proposed by researchers, between the peel-off and rip-off end-debonding types of failure. The peel-off failure is generally characterized by a failure plane located within the first few millimetres of the concrete cover, whilst the rip-off failure penetrates deeper into the concrete cover and propagates along the tensile steel reinforcement. A new rip-off strength model is described in this paper. The model proposed is based on the Chen and Teng peel-off model and relies upon additional theoretical considerations. The influence of the amount of the internal tensile steel reinforcement and the effective anchorage length of FRP are considered and discussed. The validity of the new model is analyzed further through comparisons with test results, findings of a numerical investigation, and a parametric study. The new rip-off strength model is assessed against a database comprising results from 62 beams tested by various researchers and is shown to yield less conservative results. Russian translation published in Mekhanika Kompozitnykh Materialov, Vol. 44, No. 3, pp. 373–388, May–June, 2008.     

The emergence of kinship behavior in structured populations of unrelated individuals

The paper provides an explanation for altruistic behavior based on the matching and learning technology in the population. In a infinite structured population, in which individuals meet and interact with their neighbors, individuals learn by imitating their more successful neighbors. We ask which strategies are robust against invasion of mutants: A strategy is unbeatable if when all play it and a finite group of identical mutants enters then the learning process eliminates the mutants with probability 1. We find that such an unbeatable strategy is necessarily one in which each individual behaves as if he is related to his neighbors and takes into account their welfare as well as his. The degree to which he cares depends on the radii of his neighborhoods. Received June 1996/Revised version October 1998