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Related papers: An improved fitting formula for the dark matter bi…

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We study the relation between the halo and matter density fields -- commonly termed bias -- in the LCDM framework. In particular, we examine the local model of biasing at quadratic order in the matter density. This model is characterized by…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Jennifer E. Pollack , Robert E. Smith , Cristiano Porciani

Computing the matter power spectrum, $P(k)$, as a function of cosmological parameters can be prohibitively slow in cosmological analyses, hence emulating this calculation is desirable. Previous analytic approximations are insufficiently…

In this work we introduce two new polynomial parametrizations of dark energy and explore their correlation properties. The parameters to fit are the equation of state values at z=0 and z=0.5, which have naturally low correlation and have…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Irene Sendra , Ruth Lazkoz

We propose an alternative approach to the construction of fitting functions to the nonlinear matter power spectrum extracted from $N$-body simulations based on the relative matter power spectrum $\delta(k,a)$, defined as the fractional…

Cosmology and Nongalactic Astrophysics · Physics 2020-03-18 Steen Hannestad , Yvonne Y. Y. Wong

Ultra-light axions (ULAs) are a promising dark-matter candidate. ULAs may have implications for small-scale challenges to the $\Lambda$CDM model, and arise in string scenarios. ULAs are already constrained by cosmic microwave background…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-30 Tessa Cookmeyer , Daniel Grin , Tristan L. Smith

We introduce an emulator approach to predict the non-linear matter power spectrum for broad classes of beyond-$\Lambda$CDM cosmologies, using only a suite of $\Lambda$CDM $N$-body simulations. By including a range of suitably modified…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-02 Benjamin Giblin , Matteo Cataneo , Ben Moews , Catherine Heymans

The growth of large-scale structure, together with the geometrical information of cosmic expansion history and cosmological distances, can be used to obtain constraints on the spatial curvature of the universe that probes the early universe…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-23 Ryo Terasawa , Ryuichi Takahashi , Takahiro Nishimichi , Masahiro Takada

The standard cosmological model, LCDM, provides an excellent fit to Cosmic Microwave Background (CMB) data. However, the model has well known problems. For example, the cosmological constant, is fine-tuned to 1 part in 10^100 and the cold…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 T. Shanks , R. W. F. Johnson , J. A. Schewtschenko , J. R. Whitbourn

We re-examine a genuine power of weak lensing bispectrum tomography for constraining cosmological parameters, when combined with the power spectrum tomography, based on the Fisher information matrix formalism. To account for the full…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-21 Issha Kayo , Masahiro Takada

This work reexamines cosmological parameter constraints from the DESI Data Release 2 baryon acoustic oscillation (BAO) measurements using the distance-basis representation (D_V/r_d, D_M/D_H), which separates the isotropic BAO scale from the…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-02 Seokcheon Lee

We present the results from combining machine learning with the profile likelihood fit procedure, using data from the Large Underground Xenon (LUX) dark matter experiment. This approach demonstrates reduction in computation time by a factor…

In this paper we present the constraints on cold dark matter (CDM) isocurvature contributions to the cosmological perturbations. By employing Markov Chain Monte Carlo method (MCMC), we perform a global analysis for cosmological parameters…

Cosmology and Nongalactic Astrophysics · Physics 2011-07-04 Hong Li , Jie Liu , Jun-Qing Xia , Yi-Fu Cai

We measure the clustering of dark matter halos in a large set of collisionless cosmological simulations of the flat LCDM cosmology. Halos are identified using the spherical overdensity algorithm, which finds the mass around isolated peaks…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Jeremy L. Tinker , Brant E. Robertson , Andrey V. Kravtsov , Anatoly Klypin , Michael S. Warren , Gustavo Yepes , Stefan Gottlober

We consider a recently proposed model in which dark matter interacts with a thermal background of dark radiation. Dark radiation consists of relativistic degrees of freedom which allow larger values of the expansion rate of the universe…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-24 Manuel A. Buen-Abad , Martin Schmaltz , Julien Lesgourgues , Thejs Brinckmann

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…

The dissipation of small-scale perturbations in the early universe produces a distortion in the blackbody spectrum of cosmic microwave background photons. In this work, we propose to use these distortions as a probe of the microphysics of…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-13 James A. D. Diacoumis , Yvonne Y. Y. Wong

In this paper we analyze a suite of cosmological simulations of modified gravitational action f(R) models, where cosmic acceleration is induced by a scalar field that acts as a fifth force on all forms of matter. In particular, we focus on…

Cosmology and Nongalactic Astrophysics · Physics 2011-11-23 Héctor Gil-Marín , Fabian Schmidt , Wayne Hu , Raul Jimenez , Licia Verde

We discuss the extension to redshift space of a rescaling algorithm, designed to alter the effective cosmology of a pre-existing simulated particle distribution or catalogue of dark matter haloes. The rescaling approach was initially…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-25 Alexander Mead , John Peacock

We further develop the description of redshift space distortions within the Effective Field Theory of Large Scale Structures. First, we generalize the counterterms to include the effect of baryonic physics and primordial non-Gaussianity.…

Cosmology and Nongalactic Astrophysics · Physics 2018-04-04 Matthew Lewandowski , Leonardo Senatore , Francisco Prada , Cheng Zhao , Chia-Hsun Chuang

Given the importance of future large scale structure surveys for delivering new cosmological information, it is crucial to reliably predict their observables. The Effective Field Theory of Large Scale Structures (EFTofLSS) provides a…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-14 Raul E. Angulo , Simon Foreman , Marcel Schmittfull , Leonardo Senatore