Article
Astronomy & Astrophysics
Andrei Lazanu
Summary: Machine learning techniques accurately extract cosmological parameters Omega(m) and sigma(8) from N-body simulations, and also find these parameters from the non-linear matter power spectrum using random forest regressors and deep neural networks. The power spectrum provides competitive results in terms of accuracy compared to using simulations, and the scalar spectral index ns can also be estimated from the power spectrum with lower precision.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Oliver H. E. Philcox, Alejandro Aviles, Elena Massara
Summary: The study presents one-loop perturbation theory for the power spectrum of the marked density field of matter and biased tracers in real- and redshift-space. The inclusion of one-loop Effective Field Theory terms substantially improves accuracy, with 5% accuracy at z = 1. The theory suggests a reorganization to include all relevant terms for large scales, leading to a sub-percent accurate model with the inclusion of free coefficients.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Guido D'Amico, Leonardo Senatore, Pierre Zhang
Summary: By applying the Effective Field Theory of Large-Scale Structure to analyze the wCDM cosmological model, competitive CMB-independent limits on parameter w were set using data from BOSS, Pantheon, and BBN. After incorporating the Planck CMB data, adjustments were made to the limits on parameter w.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Rebeca Martinez-Carrillo, Juan Carlos Hidalgo, Karim A. Malik, Alkistis Pourtsidou
Summary: The researchers compute the real space galaxy power spectrum, including the effects of General Relativity and primordial non-Gaussianity through parameters f(NL) and g(NL), and assess the detectability of these contributions in Stage-IV surveys. They also found that specific values of the bias parameter may erase the primordial and relativistic contributions to the configuration space power spectrum.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Elena Kozlikin, Robert Lilow, Felix Fabis, Matthias Bartelmann
Summary: By comparing the newly developed particle-based Kinetic Field Theory with the established Eulerian Standard Perturbation Theory, we find that in the non-interacting regime of free-streaming kinematics, Kinetic Field Theory contains a complete resummation of Standard Perturbation Theory, and the exact solution of Kinetic Field Theory cannot be recovered in any finite order of Standard Perturbation Theory. This suggests that Kinetic Field Theory may provide a better starting point for perturbative treatments of non-linear structure formation.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Jaiyul Yoo, Nastassia Grimm, Ermis Mitsou
Summary: This study investigates the three-point correlation function of observed matter density fluctuations in a squeezed triangular configuration in a Lambda CDM universe under a single-field inflationary scenario. The study finds that the theoretical descriptions of galaxy bias in general relativity are incomplete due to ambiguities in spatial gauge choice, and a proper relativistic description of galaxy bias is needed for definitive conclusions in galaxy clustering. Additionally, it demonstrates that gauge-invariant calculations of cosmological observables are unaffected by extra coordinate transformations and that relativistic effects associated with light propagation cancel each other.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Pedro Carrilho, Chiara Moretti, Benjamin Bose, Katarina Markovic, Alkistis Pourtsidou
Summary: Interacting dark energy models are proposed as alternatives to ACDM, and forthcoming galaxy clustering surveys will provide constraints on these models. This study compares three approaches of modeling non-linearities, considering a model with a simple 1-parameter extension to wCDM. Analysis using simulated data shows that the EFTofLSS-based model is better at describing data up to smaller scales and extracting more information, forecasting uncertainties on the dark energy equation of state and interaction parameter.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Luca Amendola, Massimo Pietroni, Miguel Quartin
Summary: We present a methodology to extend Fisher matrix forecasts to mildly non-linear scales without the need for selecting a cosmological model. By utilizing standard non-linear perturbation theory and assuming accurate measurements of cosmological distances, we parametrize the linear power spectrum and the growth rate in various k and z bins, obtaining model-independent constraints on the expansion rate and growth rate. Application of this technique to the Euclid and DESI specifications shows significant improvements in precision, especially when extending to higher k values. The absolute precision achieved for the expansion rate and growth rate at each redshift range is also discussed, highlighting the importance of considering non-linear corrections.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Anton Baleato Lizancos, Martin White
Summary: A leading method to constrain physical theories from cosmological observations is to test their predictions for the angular clustering statistics of matter tracers. This article explores the impact of anisotropies in the redshift distribution on angular two-point statistics, identifying a mode-coupling effect that adds power to auto-correlations and removes it from certain cross-correlations. The study also discusses special cases like galaxy clustering and cosmic shear and releases a code to compute the biases.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Florian Beutler, Patrick McDonald
Summary: Recent developments in galaxy redshift surveys have led to the proposal of a matrix-based analysis framework for galaxy power spectrum multipoles, providing deconvolved power spectrum results for several datasets. The use of deconvolved power spectrum multipoles allows for a data analysis independent of survey-specific aspects, such as the window function. This alternative analysis method has been shown to yield similar results to standard analysis in the case of the BOSS dataset, with various analysis components and a Python toolbox provided for convenience.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Fabian Schmidt
Summary: A forward model for matter and biased tracers at arbitrary order in Lagrangian perturbation theory is introduced, including complete LPT displacement field and relevant bias operators. Validation tests show subpercent agreement with N-body simulations, demonstrating the effectiveness and accuracy of the model. This method has broad applications in cosmology research.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Theo Simon, Pierre Zhang, Vivian Poulin
Summary: This study presents cosmological results obtained from analyzing the power spectrum of eBOSS quasars using effective-field theory (EFT). The analysis provides constraints on various parameters such as matter abundance, Hubble constant, and clustering amplitude, which are consistent with previous studies. By combining with other data sources, the constraints are further improved, leading to more stringent bounds on parameters like neutrino mass.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Pierre Zhang, Yifu Cai
Summary: The study re-analyzed the full shape of the BOSS galaxy two-point function within Lambda-CDM, with results constraining various cosmological parameters. The effect of redshift selection on the results was discussed, emphasizing the importance of systematic assessments for ongoing and future large-volume surveys.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Byeonghee Yu, Uros Seljak, Yin Li, Sukhdeep Singh
Summary: We present growth of structure constraints from the cosmological analysis of the power spectrum multipoles of SDSS-III BOSS DR12 galaxies. We use a galaxy power spectrum model that decomposes galaxies into halo mass bins and combines perturbation theory and halo model to model halo clustering. By constraining a single parameter f sigma 8 to Planck+BAO prior, we reduce the effects of prior volume and mismodeling. Our analysis yields tight constraints on f sigma 8 and discusses the sensitivity of cosmological parameter estimation to various factors.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Srijita Sinha, Narayan Banerjee
Summary: In this study, perturbations in a scalar field model driving recent acceleration were investigated, revealing distinctive qualitative features compared to the traditional ΛCDM model, particularly in reducing the amplitude of the matter power spectrum at an 8h(-1) Mpc scale.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Alexandre Barreira, Dylan Nelson, Annalisa Pillepich, Volker Springel, Fabian Schmidt, Ruediger Pakmor, Lars Hernquist, Mark Vogelsberger
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2019)
Article
Astronomy & Astrophysics
Alexandre Barreira, Giovanni Cabass, Dylan Nelson, Fabian Schmidt
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2020)
Article
Astronomy & Astrophysics
Stefan Hilbert, Alexandre Barreira, Giulio Fabbian, Pablo Fosalba, Carlo Giocoli, Sownak Bose, Matteo Calabrese, Carmelita Carbone, Christopher T. Davies, Baojiu Li, Claudio Llinares, Pierluigi Monaco
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2020)
Article
Astronomy & Astrophysics
Alexandre Barreira, Giovanni Cabass, Kaloian D. Lozanov, Fabian Schmidt
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2020)
Article
Astronomy & Astrophysics
Simon Foreman, William Coulton, Francisco Villaescusa-Navarro, Alexandre Barreira
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2020)
Article
Astronomy & Astrophysics
Alexandre Barreira
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2020)
Article
Astronomy & Astrophysics
Alexandre Barreira, Giovanni Cabass, Fabian Schmidt, Annalisa Pillepich, Dylan Nelson
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2020)
Review
Physics, Multidisciplinary
Tessa Baker, Alexandre Barreira, Harry Desmond, Pedro Ferreira, Bhuvnesh Jain, Kazuya Koyama, Baojiu Li, Lucas Lombriser, Andrina Nicola, Jeremy Sakstein, Fabian Schmidt
Summary: The Novel Probes Project aims to advance the field of astrophysical tests of the dark sector by connecting observers and theorists. This review focuses on tests of gravity in the weak-field regime, ranging from stars to quasilinear cosmological scales, and complements strong-field tests of gravity as well as background and linear probes in cosmology. It discusses the potential and challenges of using astrophysical probes for tests of gravity, with a focus on nonlinear dynamics and screening mechanisms in modified-gravity models.
REVIEWS OF MODERN PHYSICS
(2021)
Article
Astronomy & Astrophysics
Alexandre Barreira, Titouan Lazeyras, Fabian Schmidt
Summary: The study uses field-level forward models of galaxy clustering and EFT likelihood formalism to infer the relations between linear bias parameters (b(1), b(2), b(K2)) in self-consistently simulated galaxies. It finds that bias relations in total mass selected objects are broadly preserved in simulated galaxies selected by various characteristics, and shows good agreement with observed galaxy samples. The use of EFT likelihood also recovers sigma(8) values from different galaxy samples, demonstrating the potential of forward models in inferring cosmological information from galaxy data.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Titouan Lazeyras, Alexandre Barreira, Fabian Schmidt
Summary: This study uses forward modeling combined with likelihood from effective-field theory to measure assembly bias in dark matter halos, finding an opposite signal in assembly bias between the tidal bias parameter b(K2) and b(1), with significant impact on the relation between b(K2) and b(1). Future studies are motivated to design better priors on b(K2)(b(1)) for cosmological constraints from galaxy clustering data.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Alexandre Barreira
Summary: In this study, hydrodynamical separate universe simulations with the IllustrisTNG model were used to predict the local primordial non-Gaussianity (PNG) bias parameters b(phi) and b(phi delta), which play a leading role in the analysis of galaxy power spectrum and bispectrum. It was found that the popular assumption of universality overpredicts the relation between b(phi delta) and linear density bias in the range of 1 ≤ b(1) ≤ 3 for dark matter halos. The study also revealed that the relations between b(phi)(b(1)) and b(phi delta)(b(1)) are redshift-dependent and sensitive to the selection of galaxies. The uncertainties in these bias parameters have a significant impact on the constraints of the local PNG parameter fnl. Moreover, it was shown that priors on galaxy bias are useful even in analyses that fit for products f(NL)b(phi) and f(NL)b(phi delta). The strategies discussed in this study can be implemented in existing f(NL) constraint analyses.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Alexandre Barreira
Summary: In this study, separate universe simulations are used to predict the local PNG bias parameters of atomic neutral hydrogen, H-I, and the results show that the sensitivity of the H-I power spectrum to f(NL) is influenced by the competition of physical effects. It is emphasized that more work is needed to assess the sensitivity on galaxy formation physics and H-I modeling strategy.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Anik Halder, Alexandre Barreira
Summary: This study introduces a new theoretical model to accurately calculate the integrated shear 3-point correlation function at small angular scales, taking into account baryonic feedback effects. The accuracy of the model is demonstrated by reproducing the measurements in simulated cosmic shear maps. The study finds that a combined analysis of the 2-point correlation function and the 3-point correlation function can significantly improve the constraints on cosmological parameters and baryonic feedback parameters.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Alexandre Barreira
Summary: The scale-dependent bias effect is a promising way to study the primordial non-Gaussianity parameter f(NL), but our limited knowledge of the linear PNG galaxy bias parameter b(phi) currently prevents us from accurately constraining f(NL).
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)