Tue, 10 Mar 2026
14:00
C3

TBA

Márton Pósfai
(Central European University)
Tue, 03 Mar 2026
14:00
C3

TBA

Bridget Smart
((Mathematical Institute University of Oxford))
Tue, 03 Feb 2026
14:00
C3

Exploring partition diversity in complex networks

Dr. Lena Mangold
(IT:U Interdisciplinary Transformation University Austria)
Abstract

Partition diversity refers to the concept that for some networks there may be multiple, similarly plausible ways to group the nodes, rather than one single best partition. In this talk, I will present two projects that address this idea from different but complementary angles. The first introduces the benchmark stochastic cross-block model (SCBM), a generative model designed to create synthetic networks with two distinct 'ground-truth' partitions. This allows us to study the extent to which existing methods for partition detection are able to reveal the coexistence of multiple underlying structures. The second project builds on this benchmark and paves the way for a Bayesian inference framework to directly detect coexisting partitions in empirical networks. By formulating this model as a microcanonical variant of the SCBM, we can evaluate how well it fits a given network compared to existing models. We find that our method more reliably detects partition diversity in synthetic networks with planted coexisting partitions, compared to methods designed to detect a single optimal partition. Together, the two projects contribute to a broader understanding of partition diversity by offering tools to explore the ambiguity of network structure.

Tue, 27 Jan 2026
14:00
C3

Social Interactions in Chimpanzees

Gesine Reinert
(Department of Statistics, University of Oxford)
Abstract
This work is based on 30 years of behavioural observations of the largest-known group of wild chimpanzees. The data includes 10 different proximity and interaction levels between chimpanzees.  There is an abrupt transition from cohesion to polarization in 2015 and the emergence of two distinct groups by 2018.
First we combine the data into a time series of a single weighted network per time stamps. Then we identify groups of individuals that stay related for a significant length of time. We detect cliques in the animal social network time series which match qualitative observations by chimpanzee experts.  Finally we introduce a simple  model to explain the split.
 
This is based on joint work with Mihai Cucuringu, Yixuan He, John Mitani, Aaron Sandel, and David Wipf.  
Tue, 10 Feb 2026
16:00
C3

TBC

Alexander Ravnanger
(Dept of Mathematical Sciences University of Copenhagen)
Abstract

to follow

Tue, 24 Feb 2026
16:00
C3

TBC

Joachim Zacharias
(University of Glasgow)
Abstract

to follow

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