43 citations · 386 across the 32 of their papers we have counts for
7 papers · 1 filter
The Optical Expansion Scalar in Cosmological Perturbation Theory
Alexander Oestreicher, Sofie Marie Koksbang
Within the geometric optics approximation, the optical expansion scalar describes the local rate of change in the amplitude of a wave or the area of a light bundle propagating thro…
Learning the averaged history of an inhomogeneous universe from its present day density field
Jonas Broe Bendtsen, Sofie Marie Koksbang
In this work, we investigate whether machine learning can be used to infer averaged cosmological quantities directly from the present day matter density distribution. Using an impl…
Cosmography for a General Spacetime Centred at Arbitrary Redshift
Jonas Broe Bendtsen, Asta Heinesen, Sofie Marie Koksbang
With upcoming surveys providing large volumes of highly precise observational data across a wide range of redshifts, it is increasingly important to have tools that can translate o…
Wave Optics Effects from Gravitational Wave Propagation Through Dark Matter Halos
Annamalai P. Shanmugaraj, Roland Haas, Erik Schnetter +1
Gravitational wave (GW) propagation is usually studied under the geometric optics approximation. But when GWs propagate through structures of sizes similar to their wavelength, thi…
A First Observational Assessment of Cosmic Backreaction Over an Extended Redshift Range
S. M. Koksbang
In the recent preprint arXiv:2604.07244v1, the authors introduce a novel combination of redshift, distance, and expansion rate observables for constraining cosmic backreaction obse…
Diagnostic Consistency Tests of the Concordance Cosmology
S. M. Koksbang, A. Heinesen
The CDM cosmological model faces increasingly significant and robust tensions among independent cosmological probes, prompting renewed scrutiny of its foundational assumptions.…
Model-independent constraints on generalized FLRW consistency relations with bootstrap-based symbolic regression
S. M. Koksbang, A. Heinesen
The standard CDM cosmological model faces increasing tensions between key observations, motivating tests that probe its underlying assumptions. In a companion letter, we present…