74 research outputs found
Social Evolution: New Horizons
Cooperation is a widespread natural phenomenon yet current evolutionary
thinking is dominated by the paradigm of selfish competition. Recent advanced
in many fronts of Biology and Non-linear Physics are helping to bring
cooperation to its proper place. In this contribution, the most important
controversies and open research avenues in the field of social evolution are
reviewed. It is argued that a novel theory of social evolution must integrate
the concepts of the science of Complex Systems with those of the Darwinian
tradition. Current gene-centric approaches should be reviewed and com-
plemented with evidence from multilevel phenomena (group selection), the
constrains given by the non-linear nature of biological dynamical systems and
the emergent nature of dissipative phenomena.Comment: 16 pages 5 figures, chapter in forthcoming open access book
"Frontiers in Ecology, Evolution and Complexity" CopIt-arXives 2014, Mexic
Shannon entropy: an econophysical approach to cryptocurrency portfolios
Cryptocurrency markets have attracted many interest for global investors
because of their novelty, wide online availability, increasing capitalization
and potential profits. In the econophysics tradition we show that many of the
most available cryptocurrencies have return statistics that do not follow
Gaussian distributions but heavy--tailed distributions instead. Entropy
measures are also applied showing that portfolio diversification is a
reasonable practice for decreasing return uncertainty.Comment: 14 pages, 5 figures, submitted to Entrop
L\'evy flights and self-similar exploratory behaviour of termite workers: beyond model fitting
Animal movements have been related to optimal foraging strategies where
self-similar trajectories are central. Most of the experimental studies done so
far have focused mainly on fitting statistical models to data in order to test
for movement patterns described by power-laws. Here we show by analyzing over
half a million movement displacements that isolated termite workers actually
exhibit a range of very interesting dynamical properties --including L\'evy
flights-- in their exploratory behaviour. Going beyond the current trend of
statistical model fitting alone, our study analyses anomalous diffusion and
structure functions to estimate values of the scaling exponents describing
displacement statistics. We evince the fractal nature of the movement patterns
and show how the scaling exponents describing termite space exploration
intriguingly comply with mathematical relations found in the physics of
transport phenomena. By doing this, we rescue a rich variety of physical and
biological phenomenology that can be potentially important and meaningful for
the study of complex animal behavior and, in particular, for the study of how
patterns of exploratory behaviour of individual social insects may impact not
only their feeding demands but also nestmate encounter patterns and, hence,
their dynamics at the social scale.Comment: 13 pages, 11 figures. Unrevised version. Final version to appear in
Plos ON
Emergence of linguistic laws in human voice
Linguistic laws constitute one of the quantitative cornerstones of modern cognitive sciences and have been routinely investigated in written corpora, or in the equivalent transcription of oral corpora. This means that inferences of statistical patterns of language in acoustics are biased by the arbitrary, language-dependent segmentation of the signal, and virtually precludes the possibility of making comparative studies between human voice and other animal communication systems.
Here we bridge this gap by proposing a method that allows to measure such patterns in acoustic signals of arbitrary origin, without needs to have access to the language corpus underneath. The method has been applied to sixteen different human languages, recovering successfully some well-known laws of human communication at timescales even below the phoneme and finding yet another link between complexity and criticality in a biological system. These methods further pave the way for new comparative studies in animal communication or the analysis of signals of unknown code.Peer ReviewedPostprint (published version
Interface Motion and Pinning in Small World Networks
We show that the nonequilibrium dynamics of systems with many interacting
elements located on a small-world network can be much slower than on regular
networks. As an example, we study the phase ordering dynamics of the Ising
model on a Watts-Strogatz network, after a quench in the ferromagnetic phase at
zero temperature. In one and two dimensions, small-world features produce
dynamically frozen configurations, disordered at large length scales, analogous
of random field models. This picture differs from the common knowledge
(supported by equilibrium results) that ferromagnetic short-cuts connections
favor order and uniformity. We briefly discuss some implications of these
results regarding the dynamics of social changes.Comment: 4 pages, 5 figures with minor corrections. To appear in Phys. Rev.
Phase transition in a stochastic prime number generator
We introduce a stochastic algorithm that acts as a prime number generator.
The dynamics of such algorithm gives rise to a continuous phase transition
which separates a phase where the algorithm is able to reduce a whole set of
integers into primes and a phase where the system reaches a frozen state with
low prime density. We present both numerical simulations and an analytical
approach in terms of an annealed approximation, by means of which the data are
collapsed. A critical slowing down phenomenon is also outlined.Comment: accepted in PRE (Rapid Comm.
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