Davide Bianchi
A5034768131- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Cosmology and Gravitation Theories
- Stellar, planetary, and galactic studies
- Gamma-ray bursts and supernovae
- Dark Matter and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- Force Microscopy Techniques and Applications
- Adaptive optics and wavefront sensing
- Scientific Research and Discoveries
- Astrophysics and Cosmic Phenomena
- Particle Detector Development and Performance
- Diamond and Carbon-based Materials Research
- Astronomical Observations and Instrumentation
- Advanced Surface Polishing Techniques
- Radiation Detection and Scintillator Technologies
- Proteoglycans and glycosaminoglycans research
- Mathematics and Applications
- Advanced Optical Sensing Technologies
- Blind Source Separation Techniques
- Nuclear Physics and Applications
- Astrophysics and Star Formation Studies
- Microbial Natural Products and Biosynthesis
- Metal and Thin Film Mechanics
- Ancient Mediterranean Archaeology and History
University of Milan
2012-2025
Mylan (Switzerland)
2024-2025
Fondazione Poliambulanza Istituto Ospedaliero
2024
Universitat de Barcelona
2019-2022
Istituto storico italiano per il Medio Evo
2021
Institut d'Estudis Espacials de Catalunya
2020
University of Portsmouth
2015-2019
AC2T Research (Austria)
2014-2018
Institut de Recherches sur la Catalyse et l'Environnement de Lyon
2016
Max Planck Institute for Extraterrestrial Physics
2016
Euclid is a space-based survey mission from the European Space Agency designed to understand origin of Universe's accelerating expansion. It will use cosmological probes investigate nature dark energy, matter and gravity by tracking their observational signatures on geometry universe cosmic history structure formation. The optimised for two independent primary probes: Weak gravitational Lensing (WL) Baryonic Acoustic Oscillations (BAO). payload consists 1.2 m Korsch telescope provide large...
The Dark Energy Spectroscopic Instrument (DESI) has embarked on an ambitious five-year survey to explore the nature of dark energy with spectroscopy 40 million galaxies and quasars. DESI will determine precise redshifts employ Baryon Acoustic Oscillation method measure distances from nearby universe z > 3.5, as well growth structure probe potential modifications general relativity. In this paper we describe significant instrumentation developed for survey. new includes a wide-field, 3.2-deg...
Abstract The Dark Energy Spectroscopic Instrument (DESI) completed its 5 month Survey Validation in 2021 May. Spectra of stellar and extragalactic targets from constitute the first major data sample DESI survey. This paper describes public release those spectra, catalogs derived properties, intermediate products. In total, includes good-quality spectral information 466,447 objects targeted as part Milky Way Survey, 428,758 Bright Galaxy 227,318 Luminous Red sample, 437,664 Emission Line...
The Dark Energy Spectroscopic Instrument (DESI) was designed to conduct a survey covering 14,000 deg$^2$ over five years constrain the cosmic expansion history through precise measurements of Baryon Acoustic Oscillations (BAO). scientific program for DESI evaluated during month Survey Validation (SV) campaign before beginning full operations. This produced deep spectra tens thousands objects from each stellar (MWS), bright galaxy (BGS), luminous red (LRG), emission line (ELG), and quasar...
The Dark Energy Spectroscopic Instrument (DESI) completed its five-month Survey Validation in May 2021. Spectra of stellar and extragalactic targets from constitute the first major data sample DESI survey. This paper describes public release those spectra, catalogs derived properties, intermediate products. In total, includes good-quality spectral information 466,447 objects targeted as part Milky Way Survey, 428,758 Bright Galaxy 227,318 Luminous Red sample, 437,664 Emission Line 76,079...
ABSTRACT We present the first comprehensive halo occupation distribution (HOD) analysis of Dark Energy Spectroscopic Instrument (DESI) One-Percent Survey luminous red galaxy (LRG) and Quasi Stellar Object (QSO) samples. constrain HOD each sample test possible extensions by fitting redshift-space 2-point correlation functions in 0.15 < r 32 h−1 Mpc a set fiducial redshift bins. use AbacusSummit cubic boxes at Planck 2018 cosmology as model templates forward clustering with AbacusHOD...
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 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 The estimation of uncertainties in cosmological parameters is an important challenge Large-Scale-Structure (LSS) analyses. For standard analyses such as Baryon Acoustic Oscillations (BAO) and Full-Shape two approaches are usually considered. First: analytical estimates the covariance matrix use Gaussian approximations (nonlinear) clustering measurements to estimate matrix, which allows a relatively fast computationally cheap way generate matrices that adapt arbitrary measurement. On...
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 We present the DESI 2024 galaxy and quasar baryon acoustic oscillations (BAO) measurements using over 5.7 million unique redshifts in range 0.1 < z 2.1. Divided by tracer type, we utilize 300,017 galaxies from magnitude-limited Bright Galaxy Survey with 0.4, 2,138,600 Luminous Red Galaxies 0.4 1.1, 2,432,022 Emission Line 0.8 1.6, 856,652 quasars 2.1, a ∼ 7,500 square degree footprint. The analysis was blinded at catalog-level to avoid confirmation bias. All fiducial choices of...
Observed galaxy clustering exhibits local transverse statistical isotropy around the line-of-sight (LOS). The variation of LOS across a survey complicates measurement observed as function angle to LOS, fast Fourier transforms (FFTs) based on Cartesian grids, cannot individually allow for this. Recent advances in methodology calculating LOS-dependent space include realization that power spectrum moments can be constructed from sums over galaxies, approximating each pair galaxies by one them....
Abstract The One-Percent survey of the Dark Energy Spectroscopic Instrument collected ∼ 270 k emission line galaxies (ELGs) at 0.8 < z 1.6. high completeness sample allowed clustering to be measured down scales never probed before, 0.04 Mpc/ h in r p for projected 2-point correlation function (2PCF) and 0.17 galaxy pair separation s 2PCF monopole quadrupole. most striking feature measurements is a strong signal smallest scales, below 0.2 1 . We analyse these data halo occupation...
The Dark Energy Spectroscopic Instrument (DESI) was designed to conduct a survey covering 14,000 deg$^2$ over five years constrain the cosmic expansion history through precise measurements of Baryon Acoustic Oscillations (BAO). scientific program for DESI evaluated during month Survey Validation (SV) campaign before beginning full operations. This produced deep spectra tens thousands objects from each stellar (MWS), bright galaxy (BGS), luminous red (LRG), emission line (ELG), and quasar...
Abstract We present constraints on the amplitude of local Primordial Non-Gaussianities (PNG), f NL , using quasar sample in Sloan Digital Sky Survey IV extended Baryon Oscillation Spectroscopic (eBOSS) Data Release 16 (DR16). analyze power spectrum monopole, testing for presence scale-dependent galaxy bias induced by PNG. Our analysis makes use optimal redshift weights that maximize response to possible non-zero find -4 < 27 at 68% confidence level, which is among strongest bounds with...
Abstract Extreme coronal line emitters (ECLEs) are a rare class of galaxy that exhibit strong, high-ionization iron emission lines in their spectra. In some cases, these transient and may be the result tidal disruption event (TDEs). To test this connection, we calculate rate variable ECLEs (vECLEs) at redshift ∼0.3. We search for Baryon Oscillation Spectroscopic Survey (BOSS) LOWZ sample discover two candidate ECLEs. Using follow-up spectra from Dark Energy Instrument Gemini Multi-Object...
We study the modelling of Halo Occupation Distribution (HOD) for eBOSS DR16 Emission Line Galaxies (ELGs). Motivated by previous theoretical and observational studies, we consider different physical effects that can change how ELGs populate haloes. explore shape average HOD, fraction satellite galaxies, their probability distribution function (PDF), density velocity profiles. Our baseline HOD was fitted to a semi-analytical model galaxy formation evolution, with decaying occupation central...
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 finite patrol...
In order to be efficient, spectroscopic galaxy redshift surveys do not obtain redshifts for all galaxies in the population targeted. The missing are often clustered, commonly leading a lower proportion of successful observations dense regions. One example is close-pair issue SDSS surveys, which have deficit pairs observed with angular separation closer than hardware limit on placing neighbouring fibres. Spatially clustered will exist next generations surveys. Various schemes previously been...
As a step towards more accurate modelling of redshift-space distortions (RSD) in galaxy surveys, we develop general description the probability distribution function pairwise velocities within framework so-called streaming model. For given separation r, such can be described as superposition virtually infinite local distributions. We characterize these terms their moments and then consider specific case which they are Gaussian functions, each with its own mean μ dispersion σ. Based on...