7,983 research outputs found
Scaling laws and universality in the choice of election candidates
Nowadays there is an increasing interest of physicists in finding
regularities related to social phenomena. This interest is clearly motivated by
applications that a statistical mechanical description of the human behavior
may have in our society. By using this framework, we address this work to cover
an open question related to elections: the choice of elections candidates
(candidature process). Our analysis reveals that, apart from the social
motivations, this system displays features of traditional out-of-equilibrium
physical phenomena such as scale-free statistics and universality. Basically,
we found a non-linear (power law) mean correspondence between the number of
candidates and the size of the electorate (number of voters), and also that
this choice has a multiplicative underlying process (lognormal behavior). The
universality of our findings is supported by data from 16 elections from 5
countries. In addition, we show that aspects of network scale-free can be
connected to this universal behavior.Comment: Accepted for publication in EP
Symbolic Sequences and Tsallis Entropy
We address this work to investigate symbolic sequences with long-range
correlations by using computational simulation. We analyze sequences with two,
three and four symbols that could be repeated times, with the probability
distribution . For these sequences, we verified that
the usual entropy increases more slowly when the symbols are correlated and the
Tsallis entropy exhibits, for a suitable choice of , a linear behavior. We
also study the chain as a random walk-like process and observe a nonusual
diffusive behavior depending on the values of the parameter .Comment: Published in the Brazilian Journal of Physic
Potts model on complex networks
We consider the general p-state Potts model on random networks with a given
degree distribution (random Bethe lattices). We find the effect of the
suppression of a first order phase transition in this model when the degree
distribution of the network is fat-tailed, that is, in more precise terms, when
the second moment of the distribution diverges. In this situation the
transition is continuous and of infinite order, and size effect is anomalously
strong. In particular, in the case of , we arrive at the exact solution,
which coincides with the known solution of the percolation problem on these
networks.Comment: 6 pages, 1 figur
Extensive Characterization of Seismic Laws in Acoustic Emissions of Crumpled Plastic Sheets
Statistical similarities between earthquakes and other systems that emit
cracking noises have been explored in diverse contexts, ranging from materials
science to financial and social systems. Such analogies give promise of a
unified and universal theory for describing the complex responses of those
systems. There are, however, very few attempts to simultaneously characterize
the most fundamental seismic laws in such systems. Here we present a complete
description of the Gutenberg-Richter law, the recurrence times, Omori's law,
the productivity law, and Bath's law for the acoustic emissions that happen in
the relaxation process of uncrumpling thin plastic sheets. Our results show
that these laws also appear in this phenomenon, but (for most cases) with
different parameters from those reported for earthquakes and fracture
experiments. This study thus contributes to elucidate the parallel between
seismic laws and cracking noises in uncrumpling processes, revealing striking
qualitative similarities but also showing that these processes display unique
features.Comment: Accepted for publication in EP
Growth patterns and scaling laws governing AIDS epidemic in Brazilian cities
Brazil holds approximately 1/3 of population living infected with AIDS
(acquired immunodeficiency syndrome) in Central and South Americas, and it was
also the first developing country to implement a large-scale control and
intervention program against AIDS epidemic. In this scenario, we investigate
the temporal evolution and current status of the AIDS epidemic in Brazil.
Specifically, we analyze records of annual absolute frequency of cases for more
than 5000 cities for the first 33 years of the infection in Brazil. We found
that (i) the annual absolute frequencies exhibit a logistic-type growth with an
exponential regime in the first few years of the AIDS spreading; (ii) the
actual reproduction number decaying as a power law; (iii) the distribution of
the annual absolute frequencies among cities decays with a power law behavior;
(iv) the annual absolute frequencies and the number of inhabitants have an
allometric relationship; (v) the temporal evolution of the annual absolute
frequencies have different profile depending on the average annual absolute
frequencies in the cities. These findings yield a general quantitative
description of the AIDS infection dynamics in Brazil since the beginning. They
also provide clues about the effectiveness of treatment and control programs
against the infection, that has had a different impact depending on the number
of inhabitants of cities. In this framework, our results give insights into the
overall dynamics of AIDS epidemic, which may contribute to select empirically
accurate models.Comment: 12 pages, 6 figure
Effective action in DSR1 quantum field theory
We present the one-loop effective action of a quantum scalar field with DSR1
space-time symmetry as a sum over field modes. The effective action has real
and imaginary parts and manifest charge conjugation asymmetry, which provides
an alternative theoretical setting to the study of the particle-antiparticle
asymmetry in nature.Comment: 8 page
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