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相关论文: Evolution mapping: a new approach to describe matt…

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We extend the evolution mapping approach, originally proposed by Sanchez (2022) to describe non-linear matter density fluctuations, to statistics of the cosmic velocity field. This framework classifies cosmological parameters into shape…

宇宙学与河外天体物理 · 物理学 2024-10-15 Matteo Esposito , Ariel G. Sánchez , Julien Bel , Andrés N. Ruiz

We introduce an extension of the evolution mapping framework to cosmological models that include massive neutrinos. The original evolution mapping framework exploits a degeneracy in the linear matter power spectrum when expressed in ${\rm…

宇宙学与河外天体物理 · 物理学 2026-02-20 A. Pezzotta , A. Eggemeier , G. Gambardella , L. Finkbeiner , A. G. Sánchez , B. Camacho Quevedo , M. Crocce , N. Lee , G. Parimbelli , R. Scoccimarro

The Eulerian cosmological fluid equations are used to study the nonlinear mode coupling of density fluctuations. We evaluate the second-order power spectrum including all four-point contributions. In the weakly nonlinear regime we find that…

天体物理学 · 物理学 2009-10-22 Bhuvnesh Jain , Edmund Bertschinger

We examine the cosmological redshift-space distortion effect on the power spectrum of the objects at high-redshifts, which is an unavoidable observational contamination in general relativistic cosmology. In particular, we consider the…

天体物理学 · 物理学 2009-10-31 Hiromitsu Magira , Y. P. Jing , Yasushi Suto

We present Aletheia, a new emulator of the non-linear matter power spectrum, $P(k)$, built upon the evolution mapping framework. This framework addresses the limitations of traditional emulation by focusing on $h$-independent cosmological…

The anisotropy of clustering in redshift space provides a direct measure of the growth rate of large scale structure in the Universe. Future galaxy redshift surveys will make high precision measurements of these distortions, and will…

宇宙学与河外天体物理 · 物理学 2010-10-28 Elise Jennings , Carlton M. Baugh , Silvia Pascoli

The current paper provides a comprehensive examination of a dark energy cosmological model in the classical regime, in which a generic scalar field is regarded as a dark energy source. Einstein's field equations are solved in model…

广义相对论与量子宇宙学 · 物理学 2022-09-07 Ritika Nagpal , Shibesh Kumar Jas Pacif , Abhishek Parida

We investigate the nonlinear evolution of structure in variants of the standard cosmological model which display damped density fluctuations relative to cold dark matter (e.g. in which cold dark matter is replaced by warm or interacting…

宇宙学与河外天体物理 · 物理学 2018-08-03 Matteo Leo , Carlton M. Baugh , Baojiu Li , Silvia Pascoli

We propose a strategy to measure the dark matter power spectrum using minimal assumptions about the galaxy distribution and the galaxy-dark matter cross-correlations. We argue that on large scales the central limit theorem generically…

天体物理学 · 物理学 2009-10-30 Ue-Li Pen

A simple speed-up cosmology model is proposed to account for the dark energy puzzle. We condense contributions from dark energy and curvature term into one effective parameter in order to reduce parameter degeneracies and to find any…

天体物理学 · 物理学 2007-10-10 Xin-He Meng , Meng Su , Zheng Wang

This paper presents a detailed theoretical study of the two-point correlation function $\xi$ for both dark matter halos and the matter density field in five cosmological models with varying matter density $\Omega_m$ and neutrino fraction…

天体物理学 · 物理学 2009-10-30 Chung-Pei Ma

We study cosmological evolution in a flat FLRW spacetime in the context of modified STEGR gravity or $f(Q)$, using an exponential two-parameter model which represents a smooth perturbative expansion around the $\Lambda$CDM model. The…

广义相对论与量子宇宙学 · 物理学 2025-04-15 Ivan R. Vasquez , A. Oliveros

Distribution of galaxies may be a biased tracer of the dark matter distribution and the relation between the galaxies and the total mass may be stochastic, non-linear and time-dependent. Since many observations of galaxy clustering will be…

天体物理学 · 物理学 2009-10-31 Atsushi Taruya

In this work we use cosmography to alleviate the degeneracy among cosmological models, proposing a way to parameterize matter and dark energy in terms of cosmokinematics quantities. The recipe of using cosmography allows to expand…

广义相对论与量子宇宙学 · 物理学 2015-12-23 Orlando Luongo , Giovanni Battista Pisani , Antonio Troisi

We present a new simple functional form to model the evolution of a spherical mass distribution in a cosmological context. Two parameters control the growth of the system and this is modelled using a redshift dependent exponential for the…

宇宙学与河外天体物理 · 物理学 2014-03-19 Hans J. T. Buist , Amina Helmi

The variation of the expansion rate of the Universe with time produces an evolution in the cosmological redshift of distant sources (for example quasar Lyman-$\alpha$ absorption lines), that might be directly observed by future ultra…

天体物理学 · 物理学 2009-11-13 A. Balbi , C. Quercellini

We determine cosmological and evolutionary parameters from the 3CR K-band Hubble diagram and K-band number counts, assuming that the galaxies in question undergo pure luminosity evolution. Separately the two data sets are highly degenerate…

天体物理学 · 物理学 2009-11-07 J. C. Jackson , Marina Dodgson

We examine the dark energy and matter densities allowed by precision measurements of distances out to various redshifts, in the presence of spatial curvature and (near) arbitrary behavior of the dark energy equation of state. Degeneracies…

宇宙学与河外天体物理 · 物理学 2011-09-22 Arman Shafieloo , Eric V. Linder

We study the nonlinear evolution of density perturbations in cosmologies where the late-time accelerated expansion is driven by a quintessence field with vanishing speed of sound. For these models matter and quintessence perturbations are…

宇宙学与河外天体物理 · 物理学 2015-05-28 Guido D'Amico , Emiliano Sefusatti

Recently a modified version of Rastall theory of gravity has been introduced in which a varying coupling parameter could act as dark energy (DE) and thus, it can be held responsible for the current accelerated expansion of the Universe.…

综合物理 · 物理学 2020-11-20 A. H. Ziaie , H. Moradpour , H. Shabani
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