Zobrazeno 1 - 10
of 165
pro vyhledávání: '"Schaefer, Bjoern Malte"'
Central to model selection is a trade-off between performing a good fit and low model complexity: A model of higher complexity should only be favoured over a simpler model if it provides significantly better fits. In Bayesian terms, this can be achie
Externí odkaz:
http://arxiv.org/abs/2407.06259
The Hubble function characterizes a given Friedmann-Robertson-Walker spacetime and can be related to the densities of the cosmological fluids and their equations of state. We show how physics-informed neural networks (PINNs) emulate this dynamical sy
Externí odkaz:
http://arxiv.org/abs/2403.13899
Tensions between cosmological parameters derived through different channels can be a genuine signature of new physics that $\Lambda$CDM as the standard model is not able to reproduce, in particular in the missing consistency between parameter estimat
Externí odkaz:
http://arxiv.org/abs/2402.19100
The intention of our paper is to provide a pedagogical application of geometric algebra to a particularly well-investigated system: We formulate the geometric and dynamical properties of Friedmann-Robertson-Walker spacetimes within the language of ge
Externí odkaz:
http://arxiv.org/abs/2402.16680
Alignments of spiral galaxies were thought to result from tidal torquing, where tidal field of the cosmic large-scale structure exert torquing moments onto dark matter haloes, determining their angular momentum and ultimately the orientation of galac
Externí odkaz:
http://arxiv.org/abs/2312.03353
Autor:
Kuntz, Rebecca Maria, Herzog, Maximilian Philipp, von Campe, Heinrich, Röver, Lennart, Schäfer, Björn Malte
Motivated by constraints on the dark energy equation of state from supernova-data, we propose a formalism for the Bayesian inference of functions: Starting at a functional variant of the Kullback-Leibler divergence we construct a functional Fisher-ma
Externí odkaz:
http://arxiv.org/abs/2306.17224
Autor:
Röver, Lennart, von Campe, Heinrich, Herzog, Maximilian Philipp, Kuntz, Rebecca Maria, Schäfer, Björn Malte
Non-Gaussian distributions in cosmology are commonly evaluated with Monte Carlo Markov-chain methods, as the Fisher-matrix formalism is restricted to the Gaussian case. The Metropolis-Hastings algorithm will provide samples from the posterior distrib
Externí odkaz:
http://arxiv.org/abs/2305.07061
Autor:
Sipp, Marvin, Schaefer, Bjoern Malte
Publikováno v:
Phys. Rev. D 107, 063538 (2023)
We reconsider the gravitational wave spectrum induced by scalar perturbations in spatially flat Friedmann-Lema\^itre-Robertson-Walker spacetimes, focusing on the matter- and $\Lambda$-dominated epochs. During matter domination, sub-horizon modes are
Externí odkaz:
http://arxiv.org/abs/2212.01190
Using the mathematical framework of information geometry, we introduce a novel method which allows one to efficiently determine the exact shape of simultaneous confidence regions for non-linearly parametrised models. Furthermore, we show how pointwis
Externí odkaz:
http://arxiv.org/abs/2211.03421
We investigate nonlinear structure formation in the fuzzy dark matter (FDM) model in comparison to cold dark matter (CDM) models from a weak lensing perspective using perturbative methods. We use Eulerian perturbation theory (PT) up to fourth order t
Externí odkaz:
http://arxiv.org/abs/2211.01523