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We present our development of Zeldovich's ideas for the measurement of the cosmological angular diameter distance (ADD) in the Friedmann Universe. We derive the general differential equation for the ADD measurement which is valid for an…

General Relativity and Quantum Cosmology · Physics 2016-04-08 Aleksey Nikolaev , Sergey Chervon

We advocate for a new paradigm of cosmological likelihood-based inference, leveraging recent developments in machine learning and its underlying technology, to accelerate Bayesian inference in high-dimensional settings. Specifically, we…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-06 Davide Piras , Alicja Polanska , Alessio Spurio Mancini , Matthew A. Price , Jason D. McEwen

The high precision attained by cosmological data in the last few years has increased the interest in exact solutions. Analytic expressions for solutions in the Standard Model are presented here for all combinations of $\Lambda = 0$,…

General Relativity and Quantum Cosmology · Physics 2009-09-29 R. Aldrovandi , R. R. Cuzinatto , L. G. Medeiros

We perform a cosmographic analysis using several cosmological observables such as the luminosity distance moduli, the volume distance, the angular diameter distance and the Hubble parameter. These quantities are determined using different…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Jun-Qing Xia , Vincenzo Vitagliano , Stefano Liberati , Matteo Viel

Cosmological parameters encoding our understanding of the expansion history of the Universe can be constrained by the accurate estimation of time delays arising in gravitationally lensed systems. We propose TD-CARMA, a Bayesian method to…

Instrumentation and Methods for Astrophysics · Physics 2023-06-14 Antoine D. Meyer , David A. van Dyk , Hyungsuk Tak , Aneta Siemiginowska

Cosmological inference becomes increasingly difficult when complex data-generating processes cannot be modeled by simple probability distributions. With the ever-increasing size of data sets in cosmology, there is increasing burden placed…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Anja Weyant , Chad Schafer , W. Michael Wood-Vasey

The $\Lambda$CDM cosmological model faces increasingly significant and robust tensions among independent cosmological probes, prompting renewed scrutiny of its foundational assumptions. While General Relativity and the nature of dark energy…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-08 S. M. Koksbang , A. Heinesen

Solving null-geodesic equations, behavior of angular diameter distances is studied in inhomogeneous cosmological models, which are given by performing N-body simulations with the CDM spectrum. The distances depend on the separation angle of…

Astrophysics · Physics 2009-10-30 Kenji Tomita

The luminosity distance in the standard cosmology as given by $\Lambda$CDM and consequently the distance modulus for supernovae can be defined by the Pad\'e approximant. A comparison with a known analytical solution shows that the Pad\'e…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-23 L. Zaninetti

This paper presents a systematic literature review focusing on the application of machine learning techniques for deriving observational constraints in cosmology. The goal is to evaluate and synthesize existing research to identify…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-14 Luis Rojas , Sebastián Espinoza , Esteban González , Carlos Maldonado , Fei Luo

We present a GPU-accelerated numerical approach for fast kernel and differential background solutions. The model image proposed in the Bramich (2008) difference image analysis algorithm is analogous to a very simple Convolutional Neural…

Instrumentation and Methods for Astrophysics · Physics 2021-05-04 James A. Hitchcock , Markus Hundertmark , Daniel Foreman-Mackey , Etienne Bachelet , Martin Dominik , Rachel Street , Yiannis Tsapras

We develop a novel analytical dynamical analysis to derive precise energy density ratio evolutions for the $\phi$CDM and $poly\Lambda$CDM models, comparing them to the standard $\Lambda$CDM model and validating against numerical solutions.…

General Relativity and Quantum Cosmology · Physics 2026-03-25 Pierros Ntelis , Jackson Levi Said

The goal of anomaly detection is to identify examples that deviate from normal or expected behavior. We tackle this problem for images. We consider a two-phase approach. First, using normal examples, a convolutional autoencoder (CAE) is…

Computer Vision and Pattern Recognition · Computer Science 2020-03-20 Natasa Sarafijanovic-Djukic , Jesse Davis

The cosmological tensions present in the $\Lambda$ cold dark matter model that have emerged and strengthened over recent years motivate model independent approaches to analysing data. Cosmography is useful for interpreting data in cosmology…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-26 Morag Hills , Asta Heinesen

Recent cosmological observations indicate that the present universe is flat and dark energy dominated. In such a universe, the calculation of the luminosity distance, d_L, involve repeated numerical calculations. In this paper, it is shown…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 T. Wickramasinghe , T. N. Ukwatta

Causal differencing has shown to be one of the promising and successful approaches towards excising curvature singularities from numerical simulations of black hole spacetimes. So far it has only been actively implemented in the ADM and…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Luis Lehner , Mijan Huq , David Garrison

We present a new model-independent method to determine the spatial curvature and to mitigate the circularity problem affecting the use of quasars as distance indicators. The cosmic-chronometer measurements are used to construct the…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-29 Jun-Jie Wei , Fulvio Melia

A functional approximation to implement Bayesian source separation analysis is introduced and applied to separation of the Cosmic Microwave Background (CMB) using WMAP data. The approximation allows for tractable full-sky map…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Simon P. Wilson , Jiwon Yoon

In our previous work, we have proposed two methods for computing the luminosity distance d_{L}^{\Lambda} in LCDM model. In this paper, two effective quadrature algorithms, known as Romberg Integration and composite Gaussian Quadrature, are…

Cosmology and Nongalactic Astrophysics · Physics 2011-12-02 Nan-Nan Yue , De-Zi Liu , Xiao-Xing Pei , Fang-Fang Zhu , Tong-Jie Zhang , Zhi-Liang Yang

We calibrate the distance and reconstruct the Hubble diagram of gamma-ray bursts (GRBs) using deep learning. We construct an artificial neural network, which combines the recurrent neural network and Bayesian neural network, and train the…

General Relativity and Quantum Cosmology · Physics 2021-11-22 Li Tang , Hai-Nan Lin , Xin Li , Liang Liu