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相关论文: Non-parametric spatial curvature inference using l…

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In this paper, we use a newly compiled sample of ultra-compact structure in radio quasars and strong gravitational lensing systems with quasars acting as background sources to constrain six spatially flat and non-flat cosmological models…

宇宙学与河外天体物理 · 物理学 2022-12-07 Tonghua Liu , Shuo Cao , Xiaolei Li , Hao Zheng , Yuting Liu , Wuzheng Guo , Chenfa Zheng

We present constraints on extensions to the flat $\Lambda$CDM cosmological model by varying the spatial curvature $\Omega_K$, the sum of the neutrino masses $\sum m_\nu$, the dark energy equation of state parameter $w$, and the Hu-Sawicki…

We reconstruct the expansion history of the Universe using type Ia supernovae (SN Ia) in a manner independent of any cosmological model assumptions. To do so, we implement a non-parametric iterative smoothing method on the Joint Light-curve…

宇宙学与河外天体物理 · 物理学 2020-08-12 Hanwool Koo , Arman Shafieloo , Ryan E. Keeley , Benjamin L'Huillier

We investigate the cosmological information in higher-order statistics of the cosmic microwave background (CMB) lensing convergence field for a near-term experiment with noise properties similar to the Simons Observatory (SO). Using a fully…

宇宙学与河外天体物理 · 物理学 2026-03-16 Shu-Fan Chen , J. Colin Hill , Zoltán Haiman

In this paper, we develop a new and effective approach to nonparametric quantile regression that accommodates ultrahigh-dimensional data arising from spatio-temporal processes. This approach proves advantageous in staving off computational…

统计方法学 · 统计学 2024-05-27 Soudeep Deb , Claudia Neves , Subhrajyoty Roy

We present a method for calculating large numbers of power spectra C_l and P(k) that accelerates CMBfast by a factor around 10^3 without appreciable loss of accuracy, then apply it to constrain 11 cosmological parameters from current Cosmic…

天体物理学 · 物理学 2009-10-07 Max Tegmark , Matias Zaldarriaga , Andrew J. S. Hamilton

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…

宇宙学与河外天体物理 · 物理学 2016-04-08 Chao-Jun Feng , Xin-Zhou Li

The possibility of an expanding decelerating Universe in the distant future is investigated in the context of a quintessence scalar field cosmology. Such a conceivable evolution is tested against SNe Ia and $H(z)$ cosmic chronometers data,…

宇宙学与河外天体物理 · 物理学 2024-01-29 A. A. Escobal , J. F. Jesus , S. H. Pereira , J. A. S. Lima

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…

宇宙学与河外天体物理 · 物理学 2019-12-18 Kai Liao , Arman Shafieloo , Ryan E. Keeley , Eric V. Linder

The current tension between early- and late-Universe measurements of the Hubble constant ($H_0$), along with the still elusive nature of dark matter and dark energy, calls for model-independent probes of the Universe's expansion history.…

Model-independent constraints on the spatial curvature are not only closely related to important problems such as the evolution of the Universe and properties of dark energy, but also provide a test of the validity of the fundamental…

宇宙学与河外天体物理 · 物理学 2018-02-28 Zhengxiang Li , Xuheng Ding , Guo-Jian Wang , Kai Liao , Zong-Hong Zhu

The spatial curvature of the Universe remains a central question in modern cosmology. In this work, we explore the potential of localized Fast Radio Bursts (FRBs) as a novel tool to constrain the cosmic curvature parameter $\Omega_k$ in a…

宇宙学与河外天体物理 · 物理学 2026-01-27 Jéferson A. S. Fortunato , Wiliam S. Hipólito-Ricaldi , Gustavo E. Romero

We present a systematic analysis of the cosmological constraints from the "Pantheon Sample" of 1048 Type Ia Supernovae (SNe Ia) in the redshift range $0.01<z<2.3$ compiled by Scolnic et al. (2018). Applying the flux-averaging method for…

宇宙学与河外天体物理 · 物理学 2019-07-10 Zhongxu Zhai , Yun Wang

We investigate the question of how tightly we can constrain the cosmological parameters by using the ``cosmic inversion'' method in which we directly reconstruct the power spectrum of primordial curvature perturbations, $P(k)$, from the…

天体物理学 · 物理学 2009-10-09 Noriyuki Kogo , Misao Sasaki , Jun'ichi Yokoyama

We present a calibration-independent test of the accelerated expansion of the universe using supernova type Ia data. The test is also model-independent in the sense that no assumptions about the content of the universe or about the…

天体物理学 · 物理学 2014-11-18 Marina Seikel , Dominik J. Schwarz

Nonlocal massive gravity can provide an interesting explanation for the late-time cosmic acceleration, with a dark energy equation of state $w_{\rm DE}$ smaller than $-1$ in the past. We derive the equations of linear cosmological…

宇宙学与河外天体物理 · 物理学 2014-08-11 Savvas Nesseris , Shinji Tsujikawa

We use the latest compilation of observational H(z) measurements obtained with cosmic chronometers in the redshift range $0<z<2$ to place constraints on cosmological parameters. We consider the sample alone and in combination with other…

宇宙学与河外天体物理 · 物理学 2019-04-15 Michele Moresco , Raul Jimenez , Licia Verde , Andrea Cimatti , Lucia Pozzetti , Claudia Maraston , Daniel Thomas

The current accelerated expansion of the Universe remains ones of the most intriguing topics in modern cosmology, driving the search for innovative statistical techniques. Recent advancements in machine learning have significantly enhanced…

宇宙学与河外天体物理 · 物理学 2025-01-03 José de Jesús Velázquez , Luis A. Escamilla , Purba Mukherjee , J. Alberto Vázquez

In this study, we use late-time probes, such as well-localized fast radio bursts (FRBs), baryon acoustic oscillations (BAO), supernovae (SNe), and cosmic chronometers (CC) to constrain cosmological parameters through a model-independent…

In the conference presentation we have reviewed the theory of non-Gaussian geometrical measures for the 3D Cosmic Web of the matter distribution in the Universe and 2D sky data, such as Cosmic Microwave Background (CMB) maps that was…

宇宙学与河外天体物理 · 物理学 2016-10-19 Dmitri Pogosyan , Sandrine Codis , Christophe Pichon