Gustavo Niz
A5034071667- Galaxies: Formation, Evolution, Phenomena
- Cosmology and Gravitation Theories
- Astronomy and Astrophysical Research
- Black Holes and Theoretical Physics
- Radio Astronomy Observations and Technology
- Scientific Research and Discoveries
- Stellar, planetary, and galactic studies
- Adaptive optics and wavefront sensing
- CCD and CMOS Imaging Sensors
- Gamma-ray bursts and supernovae
- Pulsars and Gravitational Waves Research
- Dark Matter and Cosmic Phenomena
- Statistical and numerical algorithms
- Particle physics theoretical and experimental studies
- Geophysics and Gravity Measurements
- Solar and Space Plasma Dynamics
- Astrophysics and Cosmic Phenomena
- Relativity and Gravitational Theory
- Computational Physics and Python Applications
- Astrophysical Phenomena and Observations
- Astronomical Observations and Instrumentation
- Optical Network Technologies
- Advanced Differential Geometry Research
- Remote Sensing in Agriculture
- Spectroscopy Techniques in Biomedical and Chemical Research
Universidad de Guanajuato
2016-2025
Universidad Nacional Autónoma de México
2024-2025
Universidad Intercontinental
2024-2025
Institut de Recherche sur les Lois Fondamentales de l'Univers
2024
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2024
CEA Paris-Saclay
2024
Perimeter Institute
2023
University of Waterloo
2023
Centre National de la Recherche Scientifique
2023
Ohio University
2023
Abstract We implement Crossing Statistics to reconstruct in a model-agnostic manner the expansion history of universe and properties dark energy, using DESI Data Release 1 (DR1) BAO data combination with one three different supernova compilations (PantheonPlus, Union3, DES-SN5YR) Planck CMB observations. Our results hint towards an evolving emergent energy behaviour, negligible presence at z ≳ 1, varying significance depending on sets combined. In all these reconstructions, cosmological...
ABSTRACT The 1D power spectrum P1D of the Ly α forest provides important information about cosmological and astrophysical parameters, including constraints on warm dark matter models, sum masses three neutrino species, thermal state intergalactic medium. We present first measurement with quadratic maximum likelihood estimator (QMLE) from Dark Energy Spectroscopic Instrument (DESI) survey early data sample. This sample 54 600 quasars is already comparable in size to largest previous studies,...
Abstract We present the technical details on how large-scale structure (LSS) catalogs are constructed from redshifts measured spectra observed by Dark Energy Spectroscopic Instrument (DESI). The LSS provide information needed to determine relative number density of DESI tracers as a function redshift and celestial coordinates and, e.g., clustering statistics. produce that weighted subsamples data, each matched `random' catalog forms an unclustered sampling probability could have those data...
Abstract We present an optimized way of producing the fast semi-analytical covariance matrices for Legendre moments two-point correlation function, taking into account survey geometry and mimicking non-Gaussian effects. validate approach on simulated (mock) catalogs different galaxy types, representative Dark Energy Spectroscopic Instrument (DESI) Data Release 1, used in 2024 analyses. find only a few percent differences between mock sample matrix our results, which can be expected given...
Abstract Baryon acoustic oscillations (BAO) provide a robust standard ruler to measure the expansion history of Universe through galaxy clustering. Density-field reconstruction is now widely adopted procedure for increasing precision and accuracy BAO detection. With goal finding optimal settings be used in DESI 2024 analysis, we assess sensitivity post-reconstruction constraints different choices our analysis configuration, performing tests on blinded data from first year observations (DR1),...
Abstract The Dark Energy Spectroscopic Instrument (DESI) will provide precise measurements of Baryon Acoustic Oscillations (BAO) to constrain the expansion history Universe and set stringent constraints on dark energy. Therefore, control global error budget due various systematic effects is required for DESI 2024 BAO analysis. In this work, we estimate level systematics induced in analysis assumed Halo Occupation Distribution (HOD) model Emission Line Galaxy (ELG) tracer. We make use mock...
Abstract In this paper, we present the estimation of systematics related to halo occupation distribution (HOD) modeling in baryon acoustic oscillations (BAO) distance measurement Dark Energy Spectroscopic Instrument (DESI) 2024 analysis. This paper focuses on study HOD for luminous red galaxies (LRG). We consider three different models LRGs, including base 5-parameter vanilla model and two extensions it, that refer as baseline extended models. The is described by 5 parameters, an...
Abstract Baryon Acoustic Oscillations can be measured with sub-percent precision above redshift two the Lyman- α (Ly ) forest auto-correlation and its cross-correlation quasar positions. This is one of key goals Dark Energy Spectroscopic Instrument (DESI) which started main survey in May 2021. We present this paper a study contaminants to Ly are mainly caused by correlated signals introduced spectroscopic data processing pipeline as well astrophysical due foreground absorption intergalactic...
Abstract Dark Energy Spectroscopic Instrument (DESI) uses more than 2.4 million Emission Line Galaxies (ELGs) for 3D large-scale structure (LSS) analyses in its Data Release 1 (DR1). Such large statistics enable thorough research on systematic uncertainties. In this study, we focus spectroscopic systematics of ELGs. The redshift success rate ( f goodz ) is the relative fraction secure redshifts among all measurements. It depends observing conditions, thus introduces non-cosmological...
Abstract We present a method to mitigate the effects of fiber assignment incompleteness in two-point power spectrum and correlation function measurements from galaxy spectroscopic surveys, by truncating small angular scales estimators. derive corresponding modified windows account for scale truncation theory prediction. validate this approach on simulations reproducing Dark Energy Spectroscopic Instrument (DESI) Data Release 1 (DR1) with without assignment. show that we recover unbiased...
Abstract When measuring the Baryon Acoustic Oscillations (BAO) scale from galaxy surveys, one typically assumes a fiducial cosmology when converting redshift measurements into comoving distances and also defining input parameters for reconstruction algorithm. A parameterised template model to be fitted is created based on (possibly different) cosmology. This reliance can considered form of data compression, then analysed allowing that true answer different assumed. In this study, we evaluate...
Abstract In preparation for the next generation of galaxy redshift surveys, and in particular year-one data release from Dark Energy Spectroscopic Instrument (DESI), we investigate consistency a variety effective field theory models that describe galaxy-galaxy power spectra space into quasi-linear regime using 1-loop perturbation theory. These are employed pipelines velocileptors , PyBird Folps ν . While these have been validated independently, detailed comparison with consistent choices has...
Abstract A critical requirement of spectroscopic large scale structure analyses is correcting for selection which galaxies to observe from an isotropic target list. This often limited by the hardware used perform survey will impose angular constraints simultaneously observable targets, requiring multiple passes all them. In SDSS this manifested solely as collision physical fibers and plugs placed in plates. DESI, there additional constraint robotic positioner controls each fiber being a...
Abstract The Dark Energy Spectroscopic Instrument (DESI) will provide unprecedented information about the large-scale structure of our Universe. In this work, we study robustness theoretical modelling power spectrum Folps , a novel effective field theory-based package for evaluating redshift space in presence massive neutrinos. We perform validation by fitting AbacusSummit high-accuracy N -body simulations Luminous Red Galaxies, Emission Line Galaxies and Quasar tracers, calibrated to...
Abstract In the era of precision cosmology, ensuring integrity data analysis through blinding techniques is paramount — a challenge particularly relevant for Dark Energy Spectroscopic Instrument (DESI). DESI represents monumental effort to map cosmic web, with goal measure redshifts tens millions galaxies and quasars. Given volume impact findings, potential confirmation bias poses significant challenge. To address this, we implement validate comprehensive blind strategy Data Release 1 (DR1),...
Abstract The large scale structure catalogs within DESI Data Release 1 (DR1) use nearly 6 million galaxies and quasars as tracers of the large-scale universe to measure expansion history with baryon acoustic oscillations growth redshift-space distortions. In order take advantage DESI's unprecedented statistical power, we must ensure that galaxy clustering measurements are unaffected by non-cosmological density fluctuations. One source spurious fluctuations comes from variation in...
Abstract DESI aims to provide one of the tightest constraints on cosmological parameters by analysing clustering more than thirty million galaxies. However, obtaining such requires special care in validating methodology and efforts reduce computational time required through data compression emulation techniques. In this work, we perform a rigorous validation PyBird power spectrum modelling code with both traditional emulated Full-Modelling approach model-independent ShapeFit approach. By...
We study spherically symmetric solutions in a covariant massive gravity model, which is candidate for ghost-free non-linear completion of the Fierz-Pauli theory. There branch that exhibits Vainshtein mechanism, recovering General Relativity below radius given by $(r_g m^2)^{1/3}$, where $m$ graviton mass and $r_g$ Schwarzschild matter source. Another exact exists, corresponding to Schwarzschild-de Sitter spacetimes curvature scale de space proportional squared graviton.
We investigate strong coupling effects in a covariant massive gravity model, which is candidate for ghost free non-linear completion of Fierz-Pauli. analyse the conditions to recover general relativity via Vainshtein mechanism weak field limit, and find three main cases depending on choice parameters. In first case, potential such that all non-linearities disappear vDVZ discontinuity cannot be avoided. second allows within macroscopic radius from source. last scalar graviton completely...
Starting from the general Horndeski action, we derive most effective theory for scalar perturbations around flat space that allows us to screen fifth forces via Vainshtein mechanism. The is described by a generalization of Galileon Lagrangian, which use study stability spherically symmetric configurations exhibiting effect. In particular, discuss phenomenological consequences scalar-tensor coupling absent in standard Lagrangian. This controls superluminality and fluctuations inside radius...
ABSTRACT We present the one-dimensional Ly α forest power spectrum measurement using first data provided by Dark Energy Spectroscopic Instrument (DESI). The sample comprises 26 330 quasar spectra, at redshift z > 2.1, contained in DESI Early Data Release and 2 months of main survey. employ a Fast Fourier Transform (FFT) estimator compare resulting to an alternative likelihood-based method companion paper. investigate methodological instrumental contaminants associated with new...
We implement Crossing Statistics to reconstruct in a model-agnostic manner the expansion history of universe and properties dark energy, using DESI Data Release 1 (DR1) BAO data combination with one three different supernova compilations (PantheonPlus, Union3, DES-SN5YR) Planck CMB observations. Our results hint towards an evolving emergent energy behaviour, negligible presence at $z\gtrsim 1$, varying significance depending on sets combined. In all these reconstructions, cosmological...
Abstract Broad absorption line quasars (BALs) exhibit blueshifted relative to a number of their prominent broad emission features. These features can contribute quasar redshift errors and add the Lyman- α (Ly ) forest that is unrelated large-scale structure. We present detailed analysis impact BALs on Baryon Acoustic Oscillation (BAO) results with Lyα from first year data Dark Energy Spectroscopic Instrument (DESI). The baseline strategy for mask all pixels associated BAL fall within...
Abstract The next generation of spectroscopic surveys is expected to achieve an unprecedented level accuracy in the measurement cosmological parameters. To avoid confirmation bias and thereby improve reliability these results, blinding procedures become a standard practice analyses such surveys. Blinding especially crucial when impact observational systematics important relative signal, detection that signal would have significant implications. This case for local primordial non-gaussianity,...