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In this work, we perform reconstruction of \( f(Q) \) gravity inspired by the New Agegraphic Dark Energy (NADE) model, aiming to account for the Universe's late time acceleration without invoking a cosmological constant. Utilizing a power…

宇宙学与河外天体物理 · 物理学 2025-07-02 Rajdeep Mazumdar , Kalyan Malakar , Mrinnoy M. Gohain , Kalyan Bhuyan

In this paper, we use genetic algorithms, a specific machine learning technique, to achieve a model-independent reconstruction of $f(T)$ gravity. By using $H(z)$ data derived from cosmic chronometers and radial Baryon Acoustic Oscillation…

宇宙学与河外天体物理 · 物理学 2025-06-09 Redouane El Ouardi , Amine Bouali , Imad El Bojaddaini , Ahmed Errahmani , Taoufik Ouali

We investigate the non-linear evolution of matter perturbations in $f(R)$ models with the Chameleon screening mechanism. The novel feature of our investigation is an iterative solution for the non-linear equation for the scalar field $\chi…

宇宙学与河外天体物理 · 物理学 2026-03-30 Sharvari Nadkarni-Ghosh , Tanush Reddy Vaka

We present a new method for extracting the true 3-d velocity and density fields from the nonlinear redshift--space projected density field. The method is based on the nonlinear, nonlocal transformation of the density field. We assume a…

天体物理学 · 物理学 2015-06-24 A. N. Taylor , M. Rowan-Robinson

The cosmological reconstruction scheme for modified $F(R)$ gravity is developed in terms of e-folding (or, redshift). It is demonstrated how any FRW cosmology may emerge from specific $F(R)$ theory. The specific examples of well-known…

高能物理 - 理论 · 物理学 2014-11-20 Shin'ichi Nojiri , Sergei D. Odintsov , Diego Saez-Gomez

For nonrigid image registration, matching the particular structures (or the outliers) that have missing correspondence and/or local large deformations, can be more difficult than matching the common structures with small deformations in the…

计算机视觉与模式识别 · 计算机科学 2013-04-16 Binjie Qin , Zhuangming Shen , Zien Zhou , Jiawei Zhou , Jiuai Sun , Hui Zhang , Mingxing Hu , Yisong Lv

We measure the redshift-space correlation function from a spectroscopic sample of 2783 emission line galaxies from the FastSound survey. The survey, which uses the Subaru Telescope and covers the redshift ranges of $1.19<z<1.55$, is the…

I present a new technique for the measurement of the growth of cosmic structures via the power spectrum of weak lensing cosmic shear. It is based on a template-fitting approach, where a redshift-dependent amplitude of lensing modulates a…

宇宙学与河外天体物理 · 物理学 2022-06-09 Stefano Camera

Let $f$ be an unknown function in $\mathbb R^2$, and $f_\epsilon$ be its reconstruction from discrete Radon transform data, where $\epsilon$ is the data sampling rate. We study the resolution of reconstruction when $f$ has a jump…

数值分析 · 数学 2021-12-21 Alexander Katsevich

We analyze Dark Energy Survey (DES) data to constrain a cosmological model where a subset of parameters -- focusing on $\Omega_m$ -- are split into versions associated with structure growth (e.g. $\Omega_m^{\rm grow}$) and expansion history…

Large-scale Fourier modes of the cosmic density field are of great value for learning about cosmology because of their well-understood relationship to fluctuations in the early universe. However, cosmic variance generally limits the…

宇宙学与河外天体物理 · 物理学 2022-01-05 Omar Darwish , Simon Foreman , Muntazir M. Abidi , Tobias Baldauf , Blake D. Sherwin , P. Daniel Meerburg

We present a novel approach for reconstructing the $f(Q)$ gravitational theory using parameterizations of the deceleration parameter or alternative options. This method enables the development of modified gravity scenarios that align with…

广义相对论与量子宇宙学 · 物理学 2025-02-26 G. G. L. Nashed

The role of an exponential function of the scalar curvature in the modified gravity is analyzed. Two models are proposed. A toy model that complies with local and cosmological constraints and gives appropriate qualitative description of the…

广义相对论与量子宇宙学 · 物理学 2020-07-15 L. N. Granda

Contrary to conformal transformations, disformal transformations can change the principal null directions of a spacetime geometry. Thus, depending on the frame a gravitational wave (GW) detector minimally couples to, the properties of GWs…

广义相对论与量子宇宙学 · 物理学 2025-02-12 Jibril Ben Achour , Mohammad Ali Gorji , Hugo Roussille

The accelerated expansion of the universe poses a significant challenge to General Relativity. Non-local modifications to gravity have emerged as a compelling class of theories to address this dark energy puzzle. Building upon earlier…

广义相对论与量子宇宙学 · 物理学 2025-11-19 Susobhan Mandal , S. Shankaranarayanan

We present a new model-independent strategy for testing the Friedmann-Lema\^{\i}tre-Robertson-Walker metric and constraining cosmic curvature, based on future time delay measurements of strongly lensed quasar-elliptical galaxy systems from…

宇宙学与河外天体物理 · 物理学 2017-04-20 Kai Liao , Zhengxiang Li , Guo-Jian Wang , Xi-Long Fan

Non-local theories of gravity have recently gained a lot of interest because they can suitably represent the behavior of gravitational interaction in the ultraviolet regime. Furthermore, at infrared scales, they give rise to notable…

星系天体物理 · 物理学 2019-03-06 K. F. Dialektopoulos , D. Borka , S. Capozziello , V. Borka Jovanović , P. Jovanović

We study whether an open FLRW Universe with a negative cosmological constant can evade the eventual recollapse characteristic of AdS-type Universe. Within a power-law realization of Fab-Four theory, we solve the background equations…

宇宙学与河外天体物理 · 物理学 2026-04-01 Yupeng Zhang , Shuxun Tian , Zhengxiang Li

We explore the shifted $f(R) (\propto R^{1+\delta})$ model with ${\delta}$ as a distinguishing physical parameter for the study of constraints at local scales. The corresponding dynamics confronted with different geodesics (null and…

宇宙学与河外天体物理 · 物理学 2022-07-05 Vipin Kumar Sharma , Murli Manohar Verma

We have developed spherically symmetric dynamical models of dwarf spheroidal galaxies using Schwarzschild's orbit superposition method. This type of modelling yields constraints both on the total mass distribution (e.g. enclosed mass and…

宇宙学与河外天体物理 · 物理学 2015-06-05 Maarten A. Breddels , A. Helmi , R. C. E. van den Bosch , G. van de Ven , G. Battaglia