Cosmology at Ruđer

Simulation of cosmic structures, on the light cone from the Big Bang until today (left), and at the present time (right). © arXiv:2409.19049

Welcome!

Cosmology at Ruđer was newly formed in 2021. We are interested in addressing the big questions in physics: what is dark matter and dark energy? What is the neutrino mass scale? Are there new long-range forces in the dark sector? New light degrees of freedom such as ultralight axions? What can we learn about the epoch of primordial inflation? How can we relate theoretical predictions to observations?

Below you find:

some details about our current research interests
a list of affiliated members

Interested in a master/PhD/seminar/internship on cosmology? We can provide guidance and (co-)supervision, also if you are not based in Zagreb, so get in contact with us!

Giovanni Cabass works at the intersection between theory and data analysis. For this, he mostly employs and advances methods from effective field theory. His main interests are:

understanding how much information lies in the perturbative forward modelling of the galaxy density field as opposed to its summary statistics
using galaxy clustering observations to constrain the physics of inflation, looking for new degrees of freedom during this epoch and their properties
recently, Giovanni is interested in learning how to apply AI and Machine Learning tools in cosmological data analysis

Cornelius Rampf focuses on fluid dynamical aspects of cosmological structure formation, with a particular emphasis on combining analytical methods and numerical approaches (like N-body simulations). Some recent branches of interest:

Perturbation theory and asymptotic methods, primarily applied within cosmology but recently extending to general fluid dynamics;
developing fast and/or accurate N-body simulation techniques for cosmic structures by incorporating analytical insights;
general relativity and large-scale structure, in particular how massive neutrinos can be efficiently modelled to sufficient accuracy.

Zvonimir Vlah works in the field of large-scale structure formation, developing novel analytical and numerical methods for analysing data from galaxy surveys. Topics of interest

perturbation theory/effective field theory methods in cosmological structure formation
understanding correlators on the sky in light of new galaxy surveys
development of nonperturbative approaches in large-scale structure formation

Affiliated members of the cosmology section:

Nov 2024 - Mar 2025 Dennis Linde visiting PhD student (Parma, 2022-2025)
Nov 2024 - Apr 2025 Szymon Juszczak, master student (Vienna, co-supervision)
Nov 2024 - Apr 2025 Michelle Anderson, master student (Vienna, co-supervision)