Are you eager to explore ecosystems and understand which species and interactions shape biodiversity? This internship offers a chance to study trophic networks, complex systems where predators and prey form intricate webs of interactions. Complex systems appear in physics, biology, ecology, and social sciences. They involve many interacting entities and display rich behaviors such as chaotic dynamics, phase transitions, and ecosystem stability. Studying them requires an interdisciplinary approach. Amid the current biodiversity crisis, theoretical analyses complement field studies by quantifying species and interaction importance. A recent study by the theoretical physics group at UTINAM (CNRS/UMLP) and iDiv (Halle-Jena-Leipzig) developed a method to identify the most influential species in trophic networks. This internship aims to extend this approach to quantify interaction importance. The intern will learn Markov-chain-based algorithms for network centrality, implement analysis tools in Fortran/C++ and/or Python, study network dynamics and stability, and collaborate across disciplines (theoretical ecology, geography, etc.). Offer: ~€700/month, up to 5 months, strong potential for continuation into a funded PhD. Supervisors: jose.lages@univ-fcomte.fr, guillaume.rollin@univ-fcomte.fr, benoit.gauzens@idiv.de Reference: Rollin et al., Methods in Ecology and Evolution 15, 1691–1703 (2024), https://doi.org/10.1111/2041-210X.14384