ELFT HÍRADÓ

[Szeminárium koordinátor <szfi-seminar AT wigner.mta.hu>]

SZFI Seminar
Karsai Márton
(Central European University)
Threshold driven modelling of social spreading phenomena
Information-communication technology provides an increasingly accurate 
picture of human interactions, allowing a detailed mapping of the underlying 
network structures that mediate contagion processes. In social contagion, 
characteristic for spreading of innovations or rumours, transmission is a 
collective phenomenon where all peers of an individual may be involved. 
Threshold models of social contagion on unweighted, static, single-layer 
networks predict large-scale cascades of adoption only for relatively sparse 
networks. Empirical social networks, however, indicate that individuals can 
maintain hundreds of ties varying in time and strength across a range of 
social contexts yet they exhibit frequent system-wide cascades of social 
contagion. We address this issue through a serious of studies [1-4] 
incorporating some of the most relevant features of empirical social networks 
into a conventional threshold model [1]. First, we consider that network ties 
appear with non-uniform weights and show that the time of cascade emergence 
depends non-monotonously on weight heterogeneities, which accelerate or 
decelerate the dynamics [2]. Further we consider edge "types" modelled as 
weighted multiplex structures and demonstrate that multiplexity can lead to 
global cascades in networks with average degree in the hundreds or thousands, 
perturbed only by a single initial adoption [3]. As a novel observation, we 
also show that in a multiplex network with increasing link density a sequence 
of re-entrant phase transitions occurs, resulting in alternating phases of 
stability and instability to global cascades. Finally, we address how 
time-varying interactions with bursty dynamics can lead to the acceleration 
and deceleration of threshold driven dynamics [4].References:[1] Z. Ruan, G. 
Iñiguez, and M. Karsai, and J. Kertész, Phys. Rev. Lett. 115, 218702 
(2015).[2] S. Unicomb, G. Iñiguez, and M. Karsai, Sci. Rep. 8, 3094 
(2018).[3] S. Unicomb, G. Iñiguez, and J. Kertész, and M. Karsai, Phys. Rev. 
E 100, 040301(R) (2019).[4] S. Unicomb, G. Iñiguez, J. P. Gleeson, and M. 
Karsai (submitted) e-print: arXiv:2007.06223.Tuesday, 6 October 2020, 10:00
video conference, https://letsmeet.wigner.hu/szeminarium
Language of the talk: English
All interested are welcome!
Róbert Juhászszfi-seminar AT wigner.mta.hu