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

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We show that measuring the proper motion of ${{\sim 2000}}$ stars within a dwarf galaxy, with an uncertainty of 1 km/s at most, can establish whether the Dark Matter (DM) density profile of the dwarf has a central core or cusp. We derive…

星系天体物理 · 物理学 2022-08-31 Ivan de Martino , Antonaldo Diaferio , Luisa Ostorero

We study the dark energy equation of state as a function of redshift in a non-parametric way, without imposing any {\it a priori} $w(z)$ (ratio of pressure over energy density) functional form. As a check of the method, we test our scheme…

宇宙学与河外天体物理 · 物理学 2014-03-05 Sergey Postnikov , Maria Giovanna Dainotti , Xavier Hernandez , Salvatore Capozziello

The $\Gamma$ growth model is an effective parameterization employed across various scientific disciplines and scales to depict growth. It has been demonstrated that the cosmic star formation rate density (CSFRD) can also be described…

Considering a quadratic parametrization of the dark energy density, we explore signatures of evolution using data from gas mass fraction in clusters, type Ia supernova, BAO and CMB. We find -- excluding CMB data -- a preference for a…

宇宙学与河外天体物理 · 物理学 2015-09-30 Victor H. Cardenas

Recent measurements of baryon acoustic oscillations (BAO) by the Dark Energy Spectroscopic Instrument (DESI) suggest a preference for a dynamic dark energy model over a cosmological constant. This conclusion emerges from the combination of…

宇宙学与河外天体物理 · 物理学 2024-07-15 Guanlin Liu , Yu Wang , Wen Zhao

Exotic dark matter (EDM) refers to a dark matter species whose equation of state deviates from zero at late times. This behavior enables it to model a variety of non-standard late-time cosmologies, offering alternatives to various dark…

宇宙学与河外天体物理 · 物理学 2025-09-24 Matteo Braglia , Xingang Chen , Abraham Loeb

The paucity of observed dwarf galaxies in the Local Group relative to the abundance of predicted dark matter halos remains one of the greatest puzzles of the LCDM paradigm. Solving this puzzle now requires not only matching the numbers of…

Future dark energy experiments will require better and more accurate theoretical predictions for the baryonic acoustic oscillations (BAO) signature in the spectrum of cosmological perturbations. Here, we use large N-body simulations of the…

We study the environmental effect of galaxy evolution as a function of the underlying 3D dark matter density for the first time at $z=2-2.5$, in which the underlying matter density is reconstructed from observed galaxies through dynamical…

星系天体物理 · 物理学 2024-07-23 Rieko Momose , Khee-Gan Lee , Benjamin Horowitz , Metin Ata , Jeyhan S. Kartaltepe

Simulated dark matter profiles are often modelled as a `NFW' density profile rather than a single power law. Recently, attention has turned to the rather rigorous power-law behaviour exhibited by the `pseudo phase-space density' of the dark…

天体物理学 · 物理学 2008-11-26 R. N. Henriksen

Several cosmic ray experiments have measured excesses in electrons and positrons, relative to standard backgrounds, for energies from ~ 10 GeV - 1 TeV. These excesses could be due to new astrophysical sources, but an explanation in which…

高能天体物理现象 · 物理学 2014-11-20 Spencer Chang , Lisa Goodenough

It is well-known that an extremely accurate parametrization of the growth function of matter density perturbations in $\Lambda$CDM cosmology, with errors below $0.25 \%$, is given by $f(a)=\Omega_{m}^{\gamma} \,(a)$ with $\gamma \simeq…

宇宙学与河外天体物理 · 物理学 2018-02-21 Miguel Aparicio Resco , Antonio L. Maroto

We introduce a two-parameter phenomenological extension of the $\Lambda$CDM model in which the equation of state parameter of the ``dust'' fluid becomes different from zero for redshifts below a transition value $z_t$. Using data from DESI…

宇宙学与河外天体物理 · 物理学 2025-07-30 Leonardo Giani , Rodrigo Von Marttens , Oliver Fabio Piattella

We investigate an extension of the $\Lambda$CDM model where the dark matter (DM) is coupled to photons, inducing a nonconservation of the numbers of particles for both species, where the DM particles are allowed to dilute throughout the…

宇宙学与河外天体物理 · 物理学 2018-08-21 Suresh Kumar , Rafael C. Nunes , Santosh Kumar Yadav

A very light boson of mass $\mathcal{O}(10^{-22})$ eV may potentially be a viable dark matter (DM) candidate which can avoid phenomenological problems associated with cold DM. Such "fuzzy DM (FDM)" may naturally be an axion with a decay…

高能物理 - 唯象学 · 物理学 2017-04-12 Hooman Davoudiasl , Christopher W. Murphy

We derive for the first time the dust mass function (DMF) in a wide redshift range, from z~0.2 up to z~2.5. In order to trace the dust emission, we start from a far-IR (160-um) Herschel selected catalogue in the COSMOS field. We estimate…

星系天体物理 · 物理学 2019-10-16 F. Pozzi , F. Calura , G. Zamorani , I. Delvecchio , C. Gruppioni , P. Santini

We investigate classes of shear-free cosmological dust models with irrotational fluid flows within the framework of $f(T)$ gravity. In particular, we use the $1 + 3$ covariant formalism and present the covariant linearised evolution and…

广义相对论与量子宇宙学 · 物理学 2022-07-27 Heba Sami , Shambel Sahlu , Amare Abebe , Peter K. S. Dunsby

Cold dark matter (CDM) is a well established paradigm to describe cosmological structure formation, and works extraordinarily well on large, linear, scales. Progressing further in dark matter physics requires being able to understand…

宇宙学与河外天体物理 · 物理学 2016-05-20 David J. E. Marsh

We build a rigorous statistical framework to provide constraints on the chemical and dust evolution parameters for nearby late-type galaxies with a wide range of gas fractions ($3\%<f_g<94\%$). A Bayesian Monte Carlo Markov Chain framework…

星系天体物理 · 物理学 2021-07-08 P. De Vis , S. J. Maddox , H. L. Gomez , A. P. Jones , L. Dunne