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Related papers: Cosmology with one galaxy? -- The ASTRID model and…

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The ages of two old galaxies (53W091, 53W069) at high redshifts are used to constrain the value of the cosmological constant in a flat universe ($\Lambda$CDM) and the density parameter $\Omega_M$ in Friedmann-Robertson-Walker (FRW) models…

Astrophysics · Physics 2009-10-31 J. S. Alcaniz , J. A. S. Lima

Asteroseismology has the capability of delivering stellar properties which would otherwise be inaccessible, such as radii, masses and thus ages of stars. When this information is coupled with classical determinations of stellar parameters,…

Solar and Stellar Astrophysics · Physics 2019-08-14 Luca Casagrande , Victor Silva Aguirre , Aldo M. Serenelli , Dennis Stello , Sofia Feltzing , Katharine J. Schlesinger

We investigate the impact of different assumptions in the modeling of one-loop galaxy bias on the recovery of cosmological parameters, as a follow up of the analysis done in the first paper of the series at fixed cosmology. We use three…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-01 Andrea Pezzotta , Martin Crocce , Alexander Eggemeier , Ariel G. Sánchez , Román Scoccimarro

We propose to use relative galaxy ages as a means of constraining cosmological parameters. By measuring the age difference between two ensembles of old galaxies at somewhat different redshifts, one could determine the derivative of redshift…

Astrophysics · Physics 2009-11-06 Raul Jimenez , Abraham Loeb

(ABRIDGED) We analyze the X-ray properties of a sample of local and high redshift galaxy clusters extracted from a large cosmological hydrodynamical simulation. This simulation has been realized using the Tree+SPH code GADGET-2 for a…

We conduct a detailed comparison of broad-band spectral energy distributions of six z >= 5.5 galaxies against galaxies drawn from cosmological hydrodynamic simulations. We employ a new tool called SPOC, which constrains the physical…

Astrophysics · Physics 2008-11-26 K. Finlator , R. Dave' , B. Oppenheimer

Astrophysical processes such as feedback from supernovae and active galactic nuclei modify the properties and spatial distribution of dark matter, gas, and galaxies in a poorly understood way. This uncertainty is one of the main theoretical…

Topological analysis of galaxy distributions has gathered increasing attention in cosmology, as they are able to capture non-Gaussian features of large-scale structures (LSS) that are overlooked by conventional two-point clustering…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-14 Jiayi Li , Cheng Zhao

The redshift distribution of galaxy lenses in known gravitational lens systems provides a powerful test that can potentially discriminate amongst cosmological models. However, applications of this elegant test have been curtailed by two…

Astrophysics · Physics 2009-06-23 Pedro R. Capelo , Priyamvada Natarajan

Every cosmology lecturer these days is confronted with teaching the modern cosmological standard model $\Lambda$CDM, and there are many approaches to do this. However, the danger is imminent that it is presented to students as something set…

Physics Education · Physics 2020-04-15 Tanja Rindler-Daller

We consider the dynamics of a cosmological substratum of pressureless matter and holographic dark energy with a cutoff length proportional to the Ricci scale. Stability requirements for the matter perturbations are shown to single out a…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 W. Zimdahl , J. C. Fabris , S. del Campo , R. Herrera

The low statistical errors on cosmological parameters promised by future galaxy surveys will only be realised with the development of new, fast, analysis methods that reduce potential systematic problems to low levels. We present an…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-23 Rossana Ruggeri , Will Percival , Héctor Gil-Marín , Fangzhou Zhu , Gongbo Zhao , Yuting Wang

We present a new machine learning model for estimating photometric redshifts with improved accuracy for galaxies in Pan-STARRS1 data release 1. Depending on the estimation range of redshifts, this model based on neural networks can handle…

Instrumentation and Methods for Astrophysics · Physics 2021-12-09 Joongoo Lee , Min-Su Shin

The abundance of galaxy clusters is in principle a powerful tool to constrain cosmological parameters, especially $\Omega_\mathrm{m}$ and $\sigma_8$, due to the exponential dependence in the high-mass regime. While the best observables are…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-23 Christian Angrick , Francesco Pace , Matthias Bartelmann , Mauro Roncarelli

We present the Cosmology and Astrophysics with MachinE Learning Simulations --CAMELS-- project. CAMELS is a suite of 4,233 cosmological simulations of $(25~h^{-1}{\rm Mpc})^3$ volume each: 2,184 state-of-the-art (magneto-)hydrodynamic…

We attempt to put constraints on different cosmological and biasing models by combining the recent clustering results of X-ray sources in the local ($z\le 0.1$) and distant universe ($z\sim 1$). To this end we compare the measured angular…

Astrophysics · Physics 2009-11-06 Spyros Basilakos

Extracting accurate cosmological information from galaxy-galaxy and galaxy-matter correlation functions on non-linear scales ($\lesssim 10 h^{-1} \mathrm{Mpc}$) requires cosmological simulations. Additionally, one has to marginalise over…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-02 Johannes U. Lange , Frank C. van den Bosch , Andrew R. Zentner , Kuan Wang , Andrew P. Hearin , Hong Guo

Cosmography is a phenomenological and relatively model-independent approach to cosmology, where physical quantities are expanded as a Taylor series in the cosmological redshift, or in related variables. Here we apply this methodology to…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-08 C. J. A. P. Martins , F. P. S. A. Ferreira , P. V. Marto

We perform a number of inter-related cosmographic fits to the legacy05 and gold06 supernova datasets. We pay particular attention to the influence of both statistical and systematic uncertainties, and also to the extent to which the choice…

General Relativity and Quantum Cosmology · Physics 2007-07-31 Celine Cattoen , Matt Visser

The power spectrum of mass density fluctuations is evaluated from the Mark III and the SFI catalogs of peculiar velocities by a maximum likelihood analysis, using parametric models for the power spectrum and for the errors. The applications…

Astrophysics · Physics 2007-05-23 Idit Zehavi , Avishai Dekel
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