9 papers
Bridging perturbation theory and simulations: initial conditions and fast integrators for cosmological simulations
Oliver Hahn
These lecture notes provide an introduction to the generation of initial conditions for cosmological N-body simulations. Starting from the definition and properties of Gaussian ran…
JZ-Tree: GPU friendly neighbour search and friends-of-friends with dual tree walks in JAX plus CUDA
Jens Stücker, Oliver Hahn, Lukas Winkler +2
Algorithms based on spatial tree traversal are widely regarded as among the most efficient and flexible approaches for many problems in CPU-based high-performance computing (HPC).…
Accurate -body simulations with local Primordial non-Gaussianities: initial conditions and aliasing
Adrian G. Adame, Santiago Avila, Violeta Gonzalez-Perez +3
New generation galaxy surveys targeting constraints on local primordial non-Gaussianity (PNG) demand -body simulations that accurately reproduce its effects. In this work, we ex…
DISCO-DJ II: a differentiable particle-mesh code for cosmology
Florian List, Oliver Hahn, Thomas Flöss +1
The mildly non-linear regime of cosmic structure formation holds much of the information that upcoming large-scale structure surveys aim to exploit, making fast and accurate predic…
Majorization theory for quasiprobabilities
Twesh Upadhyaya, Zacharie Van Herstraeten, Jack Davis +3
Majorization theory is a powerful mathematical tool to compare the disorder in distributions, with wide-ranging applications in many fields including mathematics, physics, informat…
Differentiable Halo Mass Prediction and the Cosmology-Dependence of Halo Mass Functions
Jim Buisman, Florian List, Oliver Hahn
Modern cosmological inference increasingly relies on differentiable models to enable efficient, gradient-based parameter estimation and uncertainty quantification. Here, we present…