PhD position on Measuring Cosmic Web Dynamics

We are advertising a 4 year PhD position within the context of the Horizon-Widera EXCOSM project on Galaxies and the Cosmic Web. The position is a dual-degree position shared between the University of Groningen, at the Kapteyn Astronomical Institute, and the University of Tartu, at Tartu Observatory. During the PhD period the first 2 years will be spent at the Kapteyn Astronomical Institute, the last 2 years at Tartu Observatory.

The PhD research project has the purpose to analyze and combine the weblike distribution of galaxies in large galaxy redshift surveys, with the corresponding velocity flows inferred from measured galaxy peculiar velocities. These measurements are to be converted into a multiscale analysis of the mass distribution, as well as that of the flow field structure, and of the force and tidal field that has been shaping the cosmic web. The basic detection algorithms to infer the overall structure of the cosmic web are the various versions of the scale-space MMF/Nexus pipeline and the stochastic Bayesian Bisous method. To improve, extend and deepen the analysis to a full dynamical inventory, a major incentive for the project is the application and adaptation of state-of-the art machine learning codes to deal with redshift distortions, intrinsic (galaxy) biases, survey selection biases and in particular the complications encountered in photometric redshift surveys.

The project is part of the EU Horizon-Widera EXCOSM project, in which Tartu Observatory, the Kapteyn Astronomical Institute at the University of Groningen, the Leibniz Institute for Astrophysics at Potsdam, and the Institute Elie Cartan at the Univ. Lorraine in Nancy, work together on the issue of the relation and interaction between galaxy formation and evolution and cosmic web environment. The PhD project will be supervised by Prof. Elmo Tempel (Tartu Observatory) and Prof. Rien van de Weygaert (Kapteyn Astronomical Institute).

We seek excellent students with a strong background in cosmology, astrophysics, physics, mathematics and/or computer sciences, who seek to obtain a Joint-PhD degree from the University of Groningen and Tartu Observatory.

To be eligible to apply, a candidate must hold a Master's or equivalent degree in Physics, Astronomy, Mathematics, Computer Science, or related field, by the starting date of the enrolment (1 May – 1 October 2025). Previous research experience and skills will be important criteria for selection. English is the common language spoken at both institutes, and proficiency in English is a requirement for acceptance.

More detailed information on the Kapteyn Astronomical Institute, Tartu Observatory, and supervisors can be found at https://www.rug.nl/research/kapteyn/ and Tartu-Observatory (https://ut.ee/en/tartu-observatory).

Programme structure: The PhD candidates will be registered at both UG and UT. The candidate will defend the PhD thesis at the University of Groningen and obtain a Joint-PhD degree from both universities. The PhD position is fully funded for four years at the level appropriate level for the stay in The Netherlands (~2 years) and Estonia (~2 years).
Degree: Candidates will be registered at the graduate schools of both universities. They will defend their PhD thesis at Groningen University and receive a joint degree from Groningen University and Tartu University.
Travel: Candidates will be encouraged and supported to present and participate in national and international conferences and summerschools. This involves participation at the Excosm workshops, summerschool and conference.
Publication: Candidates are expected to publish at least three to four peer-review journal papers by the end of their studies.
Starting Date: The position is intended to start on 1 September 2025. Earlier dates are possible.