38,893 research outputs found
A trust model for spreading gossip in social networks
We introduce here a multi-type bootstrap percolation model, which we call
T-Bootstrap Percolation (T-BP), and apply it to study information propagation
in social networks. In this model, a social network is represented by a graph G
whose vertices have different labels corresponding to the type of role the
person plays in the network (e.g. a student, an educator, etc.). Once an
initial set of vertices of G is randomly selected to be carrying a gossip (e.g.
to be infected), the gossip propagates to a new vertex provided it is
transmitted by a minimum threshold of vertices with different labels. By
considering random graphs, which have been shown to closely represent social
networks, we study different properties of the T-BP model through numerical
simulations, and describe its implications when applied to rumour spread, fake
news, and marketing strategies.Comment: 9 pages, 9 figure
Sudden violation of the CHSH inequality in a two qubits system
I study the dynamics of the violation of the CHSH inequality for two qubits
interacting with a common zero-temperature non-Markovian environment. I
demonstrate sudden violation of the inequality for two qubits initially
prepared in a factorized state. Due to the strong coupling between the qubits
and the reservoir, the dynamics is characterized by numerous sharp revivals.
Furthermore I focus on a more realistic physical system in which the
spontaneous emission for the qubits is taken into account. When including
spontaneous emission even for small decay parameters, revivals in the violation
are heavily damped out. If the decay rates exceed a certain threshold, the
inequality turns out to be always satisfied.Comment: Accepted by Physica Scripta as part of the Proceedings of CEWQO0
The Phone Walkers: A study of human dependence on inactive mobile devices
The development of mobile phones has largely increased human interactions.
Whilst the use of these devices for communication has received significant
attention, there has been little analysis of more passive interactions. Through
census data on casual social groups, this work suggests a clear pattern of
mobile phones being carried in people's hands, without the person using it
(that is, not looking at it). Moreover, this study suggests that when
individuals join members of the opposite sex there is a clear tendency to stop
holding mobile phones whilst walking. Although it is not clear why people hold
their phones whilst walking in such large proportions (38% of solitary women,
and 31% of solitary men), we highlight several possible explanation for holding
the device, including the need to advertise status and affluence, to maintain
immediate connection with friends and family, and to mitigate feelings related
to anxiety and security.Comment: To appear in "Behaviour". 21 pages; 7 figures; Appendix in journal
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Nonabelianization of Higgs bundles
The character varieties of representations of a surface group into the Lie
groups SL(m,H), SO(2m,H) and Sp(m,m) have a holomorphic description in terms of
the moduli space of Higgs bundles. We show that the fibres of the integrable
system in these cases are not abelian varieties, but are instead moduli spaces
of rank 2 bundles on a spectral curve, satisfying natural stability conditions
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