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相关论文: Non-Parametric Analysis for the Dark Matter Densit…

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The stability of particles in the cosmic soup is an important property that can affect the cosmic evolution. In this work, we update the constraints on the decaying cold dark matter scenario, when the decay products are effectively…

宇宙学与河外天体物理 · 物理学 2022-11-16 S. Alvi , T. Brinckmann , M. Gerbino , M. Lattanzi , L. Pagano

We present a low-redshift-agnostic compression of anisotropic baryon acoustic oscillation (BAO) distances to constrain the normalized dark-energy density evolution, $X(z)\equiv \rho_{\rm DE}(z)/\rho_{\rm DE}(0)$, above the lowest BAO…

宇宙学与河外天体物理 · 物理学 2026-04-09 Qian-Mo Liu , Gong-Bo Zhao

We consider decaying dark matter (DDM) as a resolution to the possible tension between cosmic microwave background (CMB) and weak lensing (WL) based determinations of the amplitude of matter fluctuations, $\sigma_8$. We perform N-body…

宇宙学与河外天体物理 · 物理学 2015-10-05 Kari Enqvist , Seshadri Nadathur , Toyokazu Sekiguchi , Tomo Takahashi

[abridged] We explore the possibility that the dark matter (DM) component in galaxies may originate fractional gravity. In such a framework, the standard law of inertia continues to hold, but the gravitational potential associated to a…

星系天体物理 · 物理学 2023-06-07 Francesco Benetti , Andrea Lapi , Giovanni Gandolfi , Paolo Salucci , Luigi Danese

Using an analytic model calibrated against numerical simulations, we calculate the central densities of dark matter halos in a ``conventional'' cold dark matter model with a cosmological constant (LCDM) and in a ``tilted'' model (TLCDM)…

天体物理学 · 物理学 2007-05-23 S. M. Khairul Alam , James S. Bullock , David H. Weinberg

In this paper, we propose a new pressure parametric model of the total cosmos energy components in a spatially flat Friedmann-Robertson-Walker (FRW) universe and then reconstruct the model into quintessence and phantom scenarios,…

宇宙学与河外天体物理 · 物理学 2019-05-14 Jun-Chao Wang , Xin-He Meng

Cosmic acceleration is widely believed to require either a source of negative pressure (i.e., dark energy), or a modification of gravity, which necessarily implies new degrees of freedom beyond those of Einstein gravity. In this paper we…

高能物理 - 理论 · 物理学 2017-06-28 Lasha Berezhiani , Justin Khoury , Junpu Wang

We derive an analytic model for the redshift evolution of linear-bias, allowing for interactions and merging of the mass-tracers, by solving a second order differential equation based on linear perturbation theory and the Friedmann-Lemaitre…

天体物理学 · 物理学 2009-11-13 S. Basilakos , M. Plionis , C. Ragone-Figueroa

Observations of gamma-ray bursts up to $z\sim 9$ are best suited to study the possible evolution of the Universe equation of state at intermediate redshifts. We apply the Combo-relation to a sample of 174 gamma ray bursts to investigate…

宇宙学与河外天体物理 · 物理学 2021-03-03 M. Muccino , L. Izzo , O. Luongo , K. Boshkayev , L. Amati , M. Della Valle , G. B. Pisani , E. Zaninoni

Cosmological models with different types of Dark Energy are becoming viable alternatives for standard models with the cosmological constant. Yet, such models are more difficult to analyze and to simulate. We present analytical…

天体物理学 · 物理学 2009-11-07 R. Mainini , A. V. Maccio' , S. A. Bonometto , A. Klypin

The particle mass of dark matter (DM) was previously constrained using kinematics of ultra-faint dwarf galaxies to $m > 3 \times 10^{-19}\,\mathrm{eV}$. This constraint, which excludes the "fuzzy" range of ultra-light dark matter from…

宇宙学与河外天体物理 · 物理学 2025-09-08 Simon May , Neal Dalal , Andrey Kravtsov

We investigate the matter density perturbation $\delta_m$ and power spectrum $P(k)$ in the running vacuum model (RVM) with the cosmological constant being a function of the Hubble parameter, given by $\Lambda = \Lambda_0 + 6 \sigma H H_0+…

宇宙学与河外天体物理 · 物理学 2016-11-09 Chao-Qiang Geng , Chung-Chi Lee

We propose a nonparametric method to determine the sign of \gamma - the redshift evolution index of dark energy. This is important for distinguishing between positive energy models, a cosmological constant, and what is generally called…

天体物理学 · 物理学 2008-11-26 Houri Ziaeepour

We investigate deviations from the cosmic distance duality relation adopting model-dependent and -independent approaches using i) a Taylor expansion, ii) a power-law parameterization, iii) a logarithmic correction, iv) a (2;1) Pad\'e…

宇宙学与河外天体物理 · 物理学 2026-05-05 Anna Chiara Alfano

Extragalactic dispersion measures (DMs) obtained from observations of fast radio bursts (FRBs) are an excellent tool for probing intergalactic medium (IGM) and for conducting cosmography. However, the DM contribution from the IGM (${\rm…

宇宙学与河外天体物理 · 物理学 2019-09-25 Jun-Jie Wei , Zhengxiang Li , He Gao , Xue-Feng Wu

: From the epoch of recombination $(z\approx 10^3)$ till today, the typical density contrasts have grown by a factor of about $10^6$ in a Friedmann universe with $\Omega=1$. However, during the same epoch the typical gravitational potential…

广义相对论与量子宇宙学 · 物理学 2009-09-25 J. S. Bagla , T. Padmanabhan

The signature of Baryon Acoustic Oscillation in the clustering of dark-matter tracers allows us to measure $(D_A(z), H(z))$ independently. Treating these as conjugate variables, we are motivated to study cosmological evolution in the phase…

宇宙学与河外天体物理 · 物理学 2025-07-17 Pankaj Chavan , Tapomoy Guha Sarkar , Chandrachud B. V. Dash , Anjan A Sen

Understanding the origin of the accelerated expansion of the Universe poses one of the greatest challenges in physics today. Lacking a compelling fundamental theory to test, observational efforts are targeted at a better characterization of…

宇宙学与河外天体物理 · 物理学 2010-12-28 Tracy Holsclaw , Ujjaini Alam , Bruno Sanso , Herbert Lee , Katrin Heitmann , Salman Habib , David Higdon

We present the dust mass function (DMF) of 15,750 galaxies with redshift $z< 0.1$, drawn from the overlapping area of the GAMA and {\it H-}ATLAS surveys. The DMF is derived using the density corrected $V_{\rm max}$ method, where we estimate…

For many analyses in cosmology it is necessary to reconstruct the likely distribution of unobserved fields, such as dark matter or non-luminous baryons, from observed luminous tracers. The dominant approach in cosmology has been to use the…

宇宙学与河外天体物理 · 物理学 2025-12-16 Jordan Krywonos , Yurii Kvasiuk , Matthew C. Johnson , Moritz Münchmeyer