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Related papers: Gaussian Process Cosmography

200 papers

Cosmography provides a direct method to map the expansion history of the Universe in a model-independent way. Recently, different kinds of observations have been used in cosmographic analyses, such as SNe Ia and gamma ray bursts…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-06 R. F. L. Holanda , J. S. Alcaniz , J. C. Carvalho

Cosmography is used in cosmological data processing in order to constrain the kinematics of the universe in a model-independent way. In this paper, we first investigate the effect of the ultraviolet (UV) and X-ray relation of a quasar on…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-11 J. P. Hu , F. Y. Wang

Gravitational time delays, observed in strong lens systems where the variable background source is multiply-imaged by a massive galaxy in the foreground, provide direct measurements of cosmological distance that are very complementary to…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-18 Tommaso Treu , Philip J. Marshall

This paper aims to put constraints on the transition redshift $z_t$, which determines the onset of cosmic acceleration, in cosmological-model independent frameworks. In order to do that, we use the non-parametric Gaussian Process method…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-20 J. F. Jesus , R. Valentim , A. A. Escobal , S. H. Pereira

We apply Gaussian processes (GP) in order to impose constraints on teleparallel gravity and its $f(T)$ extensions. We use available $H(z)$ observations from (i) cosmic chronometers data (CC); (ii) Supernova Type Ia (SN) data from the…

General Relativity and Quantum Cosmology · Physics 2021-02-03 Rebecca Briffa , Salvatore Capozziello , Jackson Levi Said , Jurgen Mifsud , Emmanuel N. Saridakis

A grand challenge of the 21st century cosmology is to accurately estimate the cosmological parameters of our Universe. A major approach to estimating the cosmological parameters is to use the large-scale matter distribution of the Universe.…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-07 Siamak Ravanbakhsh , Junier Oliva , Sebastien Fromenteau , Layne C. Price , Shirley Ho , Jeff Schneider , Barnabas Poczos

Analysis of cosmic shear is an integral part of understanding structure growth across cosmic time, which in-turn provides us with information about the nature of dark energy. Conventional methods generate \emph{shear maps} from which we can…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-02 Gregory Sallaberry , Benjamin W. Priest , Robert Armstrong , Michael D. Schneider , Amanda Muyskens , Trevor Steil , Keita Iwabuchi

The cosmic curvature density parameter has been constrained in the present work independent of any background cosmological model. The reconstruction is performed adopting the non-parametric Gaussian Processes (GP). The constraints on…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-18 Purba Mukherjee , Narayan Banerjee

The study of cosmic expansion history and the late time cosmic acceleration from observational data depends on the nuisance parameters associated with the data. For example, the absolute peak magnitude of type Ia supernova associated with…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-19 Bikash R. Dinda

A model-independent or non-parametric approach for modeling a database has been widely used in cosmology. In these scenarios, the data has been used directly to reconstruct an underlying function. In this work, we introduce a novel…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-19 Ahmad Mehrabi

The last two decades have seen a major expansion in the availability, size, and precision of time-domain datasets in astronomy. Owing to their unique combination of flexibility, mathematical simplicity and comparative robustness, Gaussian…

Instrumentation and Methods for Astrophysics · Physics 2022-11-11 Suzanne Aigrain , Daniel Foreman-Mackey

Gaussian process is a theoretically appealing model for nonparametric analysis, but its computational cumbersomeness hinders its use in large scale and the existing reduced-rank solutions are usually heuristic. In this work, we propose a…

Machine Learning · Statistics 2015-11-25 Leo L. Duan , Xia Wang , Rhonda D. Szczesniak

To probe the late evolution history of the Universe, we adopt two kinds of optimal basis systems. One of them is constructed by performing the principle component analysis (PCA) and the other is build by taking the multidimensional scaling…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-08 Chao-Jun Feng , Xin-Zhou Li

Transmission spectroscopy, which consists of measuring the wavelength-dependent absorption of starlight by a planet's atmosphere during a transit, is a powerful probe of atmospheric composition. However, the expected signal is typically…

Earth and Planetary Astrophysics · Physics 2015-05-30 N. P. Gibson , S. Aigrain , S. Roberts , T. M. Evans , M. Osborne , F. Pont

As a classical approach, the dynamics of the Universe, influenced by its dark components, are unveiled through prior modifications of Einstein's equations. Cosmography, on the other hand, is a highly efficient tool for reconstructing any…

General Relativity and Quantum Cosmology · Physics 2024-07-19 Sai Swagat Mishra , N. S. Kavya , P. K. Sahoo , V. Venkatesha

The standard concordance model of the Universe is based on the cosmological constant as the driver of accelerating expansion. This concordance model is being subjected to a growing range of inter-locking observations. In addition to using…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Sahba Yahya , Marina Seikel , Chris Clarkson , Roy Maartens , Mathew Smith

With the development of new remote sensing technology, large or even massive spatial datasets covering the globe become available. Statistical analysis of such data is challenging. This article proposes a semiparametric approach to model…

Methodology · Statistics 2019-10-24 Pulong Ma , Emily L. Kang

Fields in cosmology, such as the matter distribution, are observed by experiments up to experimental noise. The first step in cosmological data analysis is usually to de-noise the observed field using an analytic or simulation driven prior.…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-29 Adam Rouhiainen , Moritz Münchmeyer

Direct observations of the Hubble rate, from cosmic chronometers and the radial baryon acoustic oscillation scale, can out-perform supernovae observations in understanding the expansion history, because supernovae observations need to be…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-26 Marina Seikel , Sahba Yahya , Roy Maartens , Chris Clarkson

Theorists are often told to express things in the "observational plane". One can do this for space-time geometry, considering "visual" observations of matter in our universe by a single observer over time, with no assumptions about…

General Relativity and Quantum Cosmology · Physics 2012-11-20 Albert Stebbins