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RESEARCH

My research operates at the intersection of statistical physics, computer science, and nonlinear dynamics and has applications to interdisciplinary problems in social, biological, and technological systems. Namely, my work falls within the fields of complex networks and sociophysics. Much of the work is theoretical, but I have been increasingly interested in using empirical data and sociological experiments to inform and validate mathematical models.Below is a description of several projects that I'm currently working on and/or interested in pursuing. I've tried to elucidate the connections between these projects as well as how they fit into my larger research agenda of developing more comprehensive and cohesive approaches within and between the fields of complex networks and sociophysics.

COMPLEX NETWORKS

Realizing that many complex systems cannot be well understood without explicitly taking into account how their components are connected can give us new insights into hard problems. My research addresses interdisciplinary, network-related problems by tackling broad theoretical issues, like the optimal deconstruction of complex networks and the detection of communities in overlapping networks, and then applying these insights toward the understanding of problems like social network construction, contagion processes, norm formation, and community fission.

Broad Theoretical Foundations

  • Deconstructing networks. What is the appropriate way to make first, second, and higher order approximations to complex networks? How does this depend on the question at hand? How do we deal with the non-independence of the statistical measures that the network community has been utilizing?
  • Global vs. local signatures of structural complexity.Many current network statistics focus on local organizational features. What are the appropriate statistics to capture global complexity?
  • Community structure in overlapping networks. In the presence of multiple networks (consider, for example, familial, friendship, and colleague networks) how can we identify the existence of and interactions between overlapping communities?
  • Robustness in complex networks
    • How does the existence of multiple, overlapping networks contribute to or detract from a system's robustness?
    • How do specialization and generalization of nodes contribute to system robustness?

Applications of complex networks

  • Social network construction. What are the rules by which social networks form?
  • Social contagion. How do fads/ideas/behaviors spread through populations?
  • Combining network and field effects. How are social cascades affected by the interaction of field effects like mass media with spread through social networks?
  • Social norms and social networks. How do social norms emerge and evolve? How do they constrained by the structure of social networks? How are social networks affected by the existence of societal norms?

SOCIOPHYSICS

Many of my current and developing research projects described above fall under the umbrella of sociophysics. Broadly speaking, sociophysics can be described as the search for fundamental laws and principles that characterize human behavior and result in collective social phenomena. Included in this field are topics such as the dynamics of complex social networks (which is how the above work ties in here), robustness of social processes, econophysics, the scaling of social systems, and the evolution of social organization. Each of these subtopics represents a union of what we call a sociophysics perspective with approaches from other fields.

So what exactly is sociophysics? Sociophysics brings a physics perspective to the problem of complex collective behaviors. Individuals are treated somewhat analogously to particles, e.g. like atoms in a gas. This allows for the application of statistical physics methodologies. The result is a coarse graining of many details of individual interactions in search of universal principles – i.e. laws of society. Of course, human behavior cannot be simplified to the extent of atoms in a gas – we likely need to include elements like adaptation and social connectivity. Identifying the appropriate elements is part of the challenge of sociophysics.

In addition to my social network interests described above, which obviously fall into the realm of sociophysics, I'm also interested in herding behavior in animals – How do local interactions between individuals lead to complex global patterns?

PAST AND PRESENT COLLABORATORS:
  • Mark Newman
  • Steve Strogatz
  • Simon Levin
  • David Krakauer
  • Jessica Flack
  • Adrian de Froment
  • Iain Couzin
  • Aaron Clauset

I'm currently looking for students and postdocs who are interested in the types of problems described above and have backgrounds in any the following areas:
  • Statistical physics
  • Applied mathematics
  • Computer science
  • Mathematical social sciences
  • Mathematical and computational biology