English
Related papers

Related papers: UNITY: Confronting Supernova Cosmology's Statistic…

200 papers

We study supernova (SN) classification using the machine learning method of the Recurrent Neural Network (RNN) in the Chinese Space Station Survey Telescope Ultra-Deep Field (CSST-UDF) photometric survey, and explore the improvement of the…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-05 Minglin Wang , Yan Gong , Dejia Zhou , Xuelei Chen

We present a cosmographic study designed to test the simplest type of accelerating cosmology: a flat universe with matter and a cosmological constant ($\Lambda$). Hubble series expansions are fit to the SCP Union2.1 supernova data set to…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-17 Brett Bochner , Damon Pappas , Menglu Dong

We investigate how the cosmological constraints from SNe Ia are improved by including the effects of weak-lensing convergence. To do so, we introduce the lognormal function as the convergence PDF modeling the lensing scatter of SN Ia…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-26 Ryuichiro Hada , Toshifumi Futamase

Type Ia supernovae (SNe Ia) are a key probe in modern cosmology, as they can be used to measure luminosity distances at gigaparsec scales. Models of their light-curves are used to project heterogeneous observed data onto a common basis for…

We discuss the possibility to identify anisotropic and/or inhomogeneous cosmological models using type Ia supernova data. A search for correlations in current type Ia peak magnitudes over a large range of angular scales yields a null…

Astrophysics · Physics 2014-11-18 Michael Blomqvist , Edvard Mortsell , Serena Nobili

We investigate observational constraints from lensing statistics and high-z type Ia supernovae on flat cosmological models with nonrelativistic matter and an exotic fluid with equation of state, $p_x=(m/3 -1)\rho_x$. We show that agreement…

Astrophysics · Physics 2008-11-26 Ioav Waga , Ana Paula M. R. Miceli

Over the past decade advancements in the understanding of several astrophysical phenomena have allowed us to infer a concordance cosmological model that successfully accounts for most of the observations of our universe. This has opened up…

Cosmology and Nongalactic Astrophysics · Physics 2011-12-13 Irène Balmès , Pier-Stefano Corasaniti

Understanding Type Ia supernovae (SNe~Ia) and the empirical standardisation relations that make them excellent distance indicators is vital to improving cosmological constraints. SN~Ia ``siblings", i.e. two or more SNe~Ia in the same host…

The latest improvements in the scale and calibration of Type Ia supernovae catalogues allow us to constrain the specific nature and evolution of dark energy through its effect on the expansion history of the universe. We present the results…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-05 Toby Lovick , Suhail Dhawan , Will Handley

Calibration uncertainties have been the leading systematic uncertainty in recent analyses using type Ia Supernovae (SNe Ia) to measure cosmological parameters. To improve the calibration, we present the application of Spectral Energy…

Uncertainty estimation is essential to make neural networks trustworthy in real-world applications. Extensive research efforts have been made to quantify and reduce predictive uncertainty. However, most existing works are designed for…

Machine Learning · Computer Science 2022-10-07 Myong Chol Jung , He Zhao , Joanna Dipnall , Belinda Gabbe , Lan Du

We investigate the impact of instrumental and astrophysical systematics on dark energy constraints derived from Type~Ia supernova (SN-Ia) observations. Using simulated datasets consistent with current SN-Ia measurements, we explore how…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-12 Drishti Sharma , Purba Mukherjee , Anjan A Sen , Suhail Dhawan

- Constraining the cosmological parameters and understanding Dark Energy have tremendous implications for the nature of the Universe and its physical laws. - The pervasive limit of systematic uncertainties reached by cosmography based on…

Bayesian graphical models are an efficient tool for modelling complex data and derive self-consistent expressions of the posterior distribution of model parameters. We apply Bayesian graphs to perform statistical analyses of Type Ia…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-15 Cong Ma , Pier-Stefano Corasaniti , Bruce A. Bassett

The main ideas behind nuclear supersymmetry are presented, starting from the basic concepts of symmetry and the methods of group theory in physics. We propose new, more stringent experimental tests that probe the supersymmetry…

Nuclear Theory · Physics 2017-11-02 A. Frank , J. Barea , R. Bijker

Constraints on dark energy from current observational data are sensitive to how distances are measured from Type Ia supernova (SN Ia) data. We find that flux-averaging of SNe Ia can be used to test the presence of unknown systematic…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-29 Yun Wang

We perform a number of inter-related cosmographic fits to the legacy05 and gold06 supernova datasets. We pay particular attention to the influence of both statistical and systematic uncertainties, and also to the extent to which the choice…

General Relativity and Quantum Cosmology · Physics 2007-07-31 Celine Cattoen , Matt Visser

While low-z Type Ia supernovae are used to measure the present rate of expansion of the Universe, high-z Type Ia measure its variation due to the cosmic matter-energy content. Results from those determinations imply a low matter density…

Astrophysics · Physics 2007-05-23 P. Ruiz-Lapuente

We present a new, cosmologically model-independent, statistical analysis of the Pantheon+ type Ia supernovae spectroscopic dataset, improving a standard methodology adopted by Lane et al. We use the Tripp equation for supernova…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-20 Antonia Seifert , Zachary G. Lane , Marco Galoppo , Ryan Ridden-Harper , David L. Wiltshire