14,820 research outputs found
Setting the Agenda: Different strategies of a Mass Media in a model of cultural dissemination
Day by day, people exchange opinions about a given new with relatives,
friends, and coworkers. In most cases, they get informed about a given issue by
reading newspapers, listening to the radio, or watching TV, i.e., through a
Mass Media (MM). However, the importance of a given new can be stimulated by
the Media by assigning newspaper's pages or time in TV programs. In this sense,
we say that the Media has the power to "set the agenda", i.e., it decides which
new is important and which is not. On the other hand, the Media can know
people's concerns through, for instance, websites or blogs where they express
their opinions, and then it can use this information in order to be more
appealing to an increasing number of people. In this work, we study different
scenarios in an agent-based model of cultural dissemination, in which a given
Mass Media has a specific purpose: To set a particular topic of discussion and
impose its point of view to as many social agents as it can. We model this by
making the Media has a fixed feature, representing its point of view in the
topic of discussion, while it tries to attract new consumers, by taking
advantage of feedback mechanisms, represented by adaptive features. We explore
different strategies that the Media can adopt in order to increase the affinity
with potential consumers and then the probability to be successful in imposing
this particular topic.Comment: 23 pages, 7 figure
Symmetry Aspects in Nonrelativistic Multi-Scalar Field Models and Application to a Coupled Two-Species Dilute Bose Gas
We discuss unusual aspects of symmetry that can happen due to entropic
effects in the context of multi-scalar field theories at finite temperature. We
present their consequences, in special, for the case of nonrelativistic models
of hard core spheres. We show that for nonrelativistic models phenomena like
inverse symmetry breaking and symmetry non-restoration cannot take place, but a
reentrant phase at high temperatures is shown to be possible for some region of
parameters. We then develop a model of interest in studies of Bose-Einstein
condensation in dilute atomic gases and discuss about its phase transition
patterns. In this application to a Bose-Einstein condensation model, however,
no reentrant phases are found.Comment: 8 pages, 1 eps figure, IOP style. Based on a talk given by R. O.
Ramos at the QFEXT05 workshop, Barcelona, Spain, September 5-9, 2005. One
reference was update
The 2d Gross-Neveu Model at Finite Temperature and Density with Finite Corrections
We use the linear expansion, or optimized perturbation theory, to
evaluate the effective potential for the two dimensional Gross-Neveu model at
finite temperature and density obtaining analytical equations for the critical
temperature, chemical potential and fermionic mass which include finite
corrections. Our results seem to improve over the traditional large-N
predictions.Comment: 7 pages, 8 figure
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