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Related papers: Gaussian Process Cosmography

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Gaussian processes are a fully Bayesian smoothing technique that allows for the reconstruction of a function and its derivatives directly from observational data, without assuming a specific model or choosing a parameterization. This is…

Cosmology and Nongalactic Astrophysics · Physics 2013-11-27 Marina Seikel , Chris Clarkson

In this letter, we propose an improved cosmological model-independent method to measure cosmic curvature, combining the recent measurements of transverse and line-of-sight directions in the baryon acoustic oscillations (BAO) with cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-09 Xiaolong Gong , Yifei Xu , Tonghua Liu , Shuo Cao , Jianyong Jiang , Yalong Nan , Ruobin Ding

The parameters of any model that satisfies the cosmological principle (the universe is homogeneous and isotropic on large scale), can be expressed through cosmographic parameters. In this paper, we perform this procedure for the Cardassian…

General Relativity and Quantum Cosmology · Physics 2017-07-27 Yu. L. Bolotin , M. I. Konchatnyi , O. A. Lemets , L. G. Zazunov

Simulation based inference has seen increasing interest in the past few years as a promising approach to model the non linear scales of galaxy clustering. The common approach using Gaussian process is to train an emulator over the…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-20 Tyann Dumerchat , Julian Bautista

Strongly lensed quasar systems with time delay measurements provide "time delay distances", which are a combination of three angular diameter distances and serve as powerful tools to determine the Hubble constant $H_0$. However, current…

Cosmology and Nongalactic Astrophysics · Physics 2019-12-18 Kai Liao , Arman Shafieloo , Ryan E. Keeley , Eric V. Linder

We study the possibility to extract model independent information about the dynamics of the universe by using Cosmography. We intend to explore it systematically, to learn about its limitations and its real possibilities. Here we are…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-19 Salvatore Capozziello , Ruth Lazkoz , Vincenzo Salzano

Inflation predicts that the Universe is spatially flat. The Planck 2018 measurements of the cosmic microwave background anisotropy favour a spatially closed universe at more than 2$\sigma$ confidence level. We use model independent methods…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-07 Yingjie Yang , Yungui Gong

Accurate estimation of the Hubble constant, and other cosmological parameters, from distances measured by cosmic gravitational wave sirens requires sufficient allowance for the dark energy evolution. We demonstrate how model independent…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-17 Ryan E. Keeley , Arman Shafieloo , Benjamin L'Huillier , Eric V. Linder

We quantify the evidence for cosmic acceleration using simulations of $H(z)$ measurements from SKA- and Euclid-like surveys. We perform a non-parametric reconstruction of the Hubble parameters and its derivative to obtain the deceleration…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-06 Carlos A. P. Bengaly

We constrain the parameters describing the kinematical state of the universe using a cosmographic approach, which is fundamental in that it requires a very minimal set of assumptions (namely to specify a metric) and does not rely on the…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Vincenzo Vitagliano , Jun-Qing Xia , Stefano Liberati , Matteo Viel

The ability to obtain reliable point estimates of model parameters is of crucial importance in many fields of physics. This is often a difficult task given that the observed data can have a very high number of dimensions. In order to…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-15 Janis Fluri , Aurelien Lucchi , Tomasz Kacprzak , Alexandre Refregier , Thomas Hofmann

The light we observe from distant astrophysical objects including supernovae and quasars allows us to determine large distances in terms of a cosmological model. Despite the success of the standard cosmological model in fitting the data,…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-07 Angela L. H. Ng

Structure formation in our Universe creates non-Gaussian random fields that will soon be observed over almost the entire sky by the Euclid satellite, the Vera-Rubin observatory, and the Square Kilometre Array. An unsolved problem is how to…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-10 Joey R. Braspenning , Elena Sellentin

Cosmological probes pose an inverse problem where the measurement result is obtained through observations, and the objective is to infer values of model parameters which characterize the underlying physical system -- our Universe. Modern…

Instrumentation and Methods for Astrophysics · Physics 2019-05-21 Timur Takhtaganov , Zarija Lukic , Juliane Mueller , Dmitriy Morozov

Gaussian processes offers a convenient way to perform nonparametric reconstructions of observational data assuming only a kernel which describes the covariance between neighbouring points in a data set. We approach the ambiguity in the…

Cosmology and Nongalactic Astrophysics · Physics 2021-08-17 Reginald Christian Bernardo , Jackson Levi Said

We use Gaussian Processes to map the expansion history of the universe in a model independent manner from the Union2.1 supernovae data and then apply these reconstructed results to solve for the growth history. By comparing this to BOSS and…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Arman Shafieloo , Alex G. Kim , Eric V. Linder

In the $\Lambda$CDM model, cosmological observations from the late and recent universe reveal a puzzling $\sim 4.5\sigma$ tension in the current rate of universe expansion. In addition to the various scenarios suggested to resolve the…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-05 Maryam Vazirnia , Ahmad Mehrabi

We measure the speed of light with current observations, such as Type Ia Supernova, galaxy ages, radial BAO mode, as well as simulations of forthcoming redshift surveys and gravitational waves as standard sirens. By means of a Gaussian…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-02 Jaiane Santos , Carlos Bengaly , Jonathan Morais , Rodrigo S. Gonçalves

Cosmography is the tool that makes possible to untie the interpretation of cosmological observations from the definition of any dynamical prior. We review the constraints on the cosmographic parameter obtained using the most thorough data…

Cosmology and Nongalactic Astrophysics · Physics 2013-03-01 Vincenzo Vitagliano , Jun-Qing Xia , Stefano Liberati , Matteo Viel

Many synoptic surveys are observing large parts of the sky multiple times. The resulting lightcurves provide a wonderful window to the dynamic nature of the universe. However, there are many significant challenges in analyzing these light…

Applications · Statistics 2016-02-04 Julian Faraway , Ashish Mahabal , Jiayang Sun , Xiaofeng Wang , Yi , Wang , Lingsong Zhang