Visiting Researchers

Reza Jafari

Reza Jafari is a faculty member of physics complex systems at the Shahid Beheshti University. He started his collaboration with DNDS in the winter of 2016. His research interests are collective behavior and crises in financial and social science, complex networks dynamics, fractional calculus and its application in networks when memory influences in the dynamics. Recently he has used fractional calculus to introduce aged networks. Indeed, age is the same as other properties of links such as weight and direction, and it can be considered a new property for a link. Evolution of social networks happens simultaneously with the variation of their links/nodes. However, sometimes it is not easy for some links/nodes to evolve in such a process because of their age. In real networks, some links/nodes can exist that are not happy with any variations. Understanding stability, aged phase transition, information transformation of social networks are some of the challenges of this project. Some other recent projects can be found on his page in ResearchGate (

Visiting Students

Cristian Candia

Hi! I'm Cristian Candia-Castro-Vallejos. I'm a Chilean physicist who also did a physics engineering program at the University of Concepcion. There, I worked on experimental physics at the center for optics and photonics. When I was in my master in physics, and also was teaching some physics classes at the University of Concepcion and University of Bio Bio, I realized that I needed to explore something else, something outside of the physics labs, so I changed my focus and I started to study econophysics. That was my entrance to the social science world. 

After finishing my master, I moved to the University of Desarrollo in Santiago and I got enrolled to the Center for Social Complexity, I got my master in social complexity science, then I moved to the MIT media lab for a year to work on my  P.hD. thesis, then I moved for six months to the Barabasi lab, to continue working on my thesis. Now, I'm finishing my Ph.D. at the Department of Network and Data Science at CEU. 

My interests are related to analytic studies on collective memory; knowledge diffusion; decision making, learning, and bullying in the education systems; evolutionary psychology; economic complexity, reality mining; science of success; collective learning; data science; social dynamics; and applied networks. Besides, I'm very interested in basketball, sailing, football, dancing, and singing (I had a band attempt and surprisingly I was the singer).

Ludovico Napoli

Ludovico is an International Master student in Physics of Complex Systems at the University of Pisa. The Master is organized in four semesters in different academic institutions: Sissa and ICTP in Trieste, Politecnico in Turin and a consortium of universities in Paris (Sorbonne, Paris VII, Paris Saclay). Ludovico has recently lost some interest in pure theoretical physics and he is now getting fascinated by the application of the quantitative tools commonly used in physics to the study of complex social and economic phenomena, and for this reason, he has come to DNDS to work on his Master’s thesis. Among other things, he loves sports (especially rowing, football, sailing, and snowboarding) and music (he plays the piano and the guitar).

Judit Varga

Judit is a PhD student in Science, Society and Technology Studies at the University of Nottingham (UK). She has a background in the behavioural and social sciences. Judit’s thesis investigates how the knowledge created through the analysis of georeferenced social media data (such as geotagged Tweets and Instagram posts) is situated in the history of human geography. It combines participant observation and bibliometric network analysis to gain a picture of how human geography researchers advocate for and against the use of such data. During her visit at DNDS, Judit aims to explore how she can apply network science methods in her project.