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相关论文: Machine Learning the Cosmic Curvature in a Model-i…

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In the context of the discrepancies between the early and late universe, we emphasize the importance of independent measurements of the cosmic curvature in the late universe. We present an investigation of the model-independent measurement…

宇宙学与河外天体物理 · 物理学 2023-09-26 Jing-Zhao Qi , Ping Meng , Jing-Fei Zhang , Xin Zhang

In this paper, we propose an improved model-independent method to constrain the cosmic curvature by combining the most recent Hubble parameter $H(z)$ and supernovae Ia (SNe Ia) data. Based on the $H(z)$ data, we first use the…

宇宙学与河外天体物理 · 物理学 2017-04-12 Jun-Jie Wei , Xue-Feng Wu

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…

宇宙学与河外天体物理 · 物理学 2021-05-07 Yingjie Yang , Yungui Gong

We propose a model-independent way to determine the cosmic curvature using the Hubble parameter $H(z)$ measured with cosmic chronometers and the comoving distance $D(z)$ inferred from HII galaxies. We employ Gaussian processes to smooth the…

宇宙学与河外天体物理 · 物理学 2019-01-18 Jing Zheng , Fulvio Melia , Tong-Jie Zhang

In this paper, we propose to estimate the spatial curvature of the universe and the cosmic opacity in a model-independent way with expansion rate measurements, $H(z)$, and type Ia supernova (SNe Ia). On the one hand, using a nonparametric…

宇宙学与河外天体物理 · 物理学 2017-10-04 Guo-Jian Wang , Jun-Jie Wei , Zheng-Xiang Li , Jun-Qing Xia , Zong-Hong Zhu

We present an improved model-independent method for determining the cosmic curvature using the observations of Baryon Acoustic Oscillations (BAOs) and the Hubble parameter. The purpose of this work is to provide insights into late-universe…

宇宙学与河外天体物理 · 物理学 2025-03-06 Tonghua Liu , Shengjia Wang , Hengyu Wu , Jieci Wang

The cosmic curvature ($\Omega_k$) is a fundamental parameter for cosmology. In this paper, we propose an improved model-independent method to constrain the cosmic curvature, which is geometrically related to the Hubble parameter $H(z)$ and…

宇宙学与河外天体物理 · 物理学 2020-10-07 Yuting Liu , Shuo Cao , Tonghua Liu , Xiaolei Li , Shuaibo Geng , Yujie Lian , Wuzheng Guo

The different spatial curvatures of the universe affect the measurement of cosmological distances, which may also contribute to explaining the observed dimming of type Ia supernovae. This phenomenon may be caused by the opacity of the…

宇宙学与河外天体物理 · 物理学 2024-01-09 Ying Yang , Tonghua Liu , Jiayuan Huang , Xiaolan Cheng , Marek Biesiada , Shu-min Wu

We propose a new model-independent method to test the cosmic curvature by comparing the proper distance and transverse comoving distance. Using the measurements of Hubble parameter $H(z)$ and angular diameter distance $d_A$, the cosmic…

宇宙学与河外天体物理 · 物理学 2016-10-11 H. Yu , F. Y. Wang

In this work, we propose a new nonparametric approach for reconstructing a function from observational data using an Artificial Neural Network (ANN), which has no assumptions about the data and is a completely data-driven approach. We test…

宇宙学与河外天体物理 · 物理学 2022-08-26 Guo-Jian Wang , Xiao-Jiao Ma , Si-Yao Li , Jun-Qing Xia

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…

宇宙学与河外天体物理 · 物理学 2024-05-09 Xiaolong Gong , Yifei Xu , Tonghua Liu , Shuo Cao , Jianyong Jiang , Yalong Nan , Ruobin Ding

Applying the distance sum rule in strong gravitational lensing (SGL) and type Ia supernova (SN Ia) observations, one can provide an interesting cosmological model-independent method to determine the cosmic curvature parameter $\Omega_k$. In…

宇宙学与河外天体物理 · 物理学 2020-07-31 Bo Wang , Jing-Zhao Qi , Jing-Fei Zhang , Xin Zhang

An approach to estimate the spatial curvature $\Omega_k$ from data independently of dynamical models is suggested, through kinematic parameterizations of the comoving distance ($D_{C}(z)$) with third degree polynomial, of the Hubble…

宇宙学与河外天体物理 · 物理学 2020-11-18 J. F. Jesus , R. Valentim , P. H. R. S. Moraes , M. Malheiro

Inferring high-fidelity constraints on the spatial curvature parameter, $\Omega_{\rm K}$, under as few assumptions as possible, is of fundamental importance in cosmology. We propose a method to non-parametrically infer $\Omega_{\rm K}$ from…

宇宙学与河外天体物理 · 物理学 2021-06-29 Suhail Dhawan , Justin Alsing , Sunny Vagnozzi

The cosmographic approach is adopted to determine the spatial curvature (i.e., $\Omega_K$) combining the latest released cosmic chronometers data (CC), the Pantheon sample of type Ia supernovae observations, and the baryon acoustic…

宇宙学与河外天体物理 · 物理学 2020-01-08 En-Kun Li , Minghui Du , Lixin Xu

We present a model-independent measurement of spatial curvature $\Omega_{k}$ in the Friedmann-Lema\^itre-Robertson-Walker (FLRW) universe, based on observations of the Hubble parameter $H(z)$ using cosmic chronometers, and a Gaussian…

宇宙学与河外天体物理 · 物理学 2019-08-23 Cheng-Zong Ruan , Fulvio Melia , Yu Chen , Tong-Jie Zhang

We use the newly published 28 observational Hubble parameter data ($H(z)$) and current largest SNe Ia samples (Union2.1) to test whether the universe is transparent. Three cosmological-model-independent methods (nearby SNe Ia method,…

宇宙学与河外天体物理 · 物理学 2013-01-15 Kai Liao , Zhengxiang Li , Jing Ming , Zong-Hong Zhu

This study aims to test the validity of general relativity (GR) on kiloparsec scales by employing a newly compiled galaxy-scale strong gravitational lensing (SGL) sample. We utilize the distance sum rule within the…

宇宙学与河外天体物理 · 物理学 2024-01-10 Jing-Yu Ran , Jun-Jie Wei

A model-independent test of the cosmic curvature parameter $\Omega_k$ is very important in cosmology. In order to estimate cosmic curvature from cosmological probes like standard candles, one has to be able to measure the luminosity…

宇宙学与河外天体物理 · 物理学 2021-02-03 Xiaogang Zheng , Shuo Cao , Yuting Liu , Marek Biesiada , Tonghua Liu , Shuaibo Geng , Yujie Lian , Wuzheng Guo

The errors of cosmological data generated from complex processes, such as the observational Hubble parameter data (OHD) and the Type Ia supernova (SN Ia) data, cannot be accurately modeled by simple analytical probability distributions,…

宇宙学与河外天体物理 · 物理学 2021-06-17 Yu-Chen Wang , Yuan-Bo Xie , Tong-Jie Zhang , Hui-Chao Huang , Tingting Zhang , Kun Liu
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