A5057027449- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Cosmology and Gravitation Theories
- Astronomical Observations and Instrumentation
- Stellar, planetary, and galactic studies
- Dark Matter and Cosmic Phenomena
- Scientific Research and Discoveries
- Adaptive optics and wavefront sensing
- History and Developments in Astronomy
- Black Holes and Theoretical Physics
- Astrophysics and Cosmic Phenomena
- Astrophysical Phenomena and Observations
- Remote Sensing in Agriculture
- Gamma-ray bursts and supernovae
- Advanced Differential Geometry Research
- Advanced Physical and Chemical Molecular Interactions
- Radio Astronomy Observations and Technology
- Statistical and numerical algorithms
- Calibration and Measurement Techniques
- Computational Physics and Python Applications
- Spectroscopy and Chemometric Analyses
- Advanced optical system design
- Space Science and Extraterrestrial Life
- Advanced Thermodynamics and Statistical Mechanics
- Impact of Light on Environment and Health
Université Paris Cité
2017-2025
Université Paris Sciences et Lettres
2017-2025
Centre National de la Recherche Scientifique
2017-2025
Istituto Nazionale di Fisica Nucleare, Sezione di Padova
2011-2025
Laboratoire Univers et Théories
2021-2025
Janssen (France)
2024-2025
University of Padua
2011-2025
Délégation Paris 7
2017-2024
Institut d'Astrophysique de Paris
2017-2024
University of Cambridge
2023
The current standard model of cosmology successfully describes a variety measurements, but the nature its main ingredients, dark matter and energy, remains unknown. is medium-class mission in Cosmic Vision 2015--2025 programme European Space Agency (ESA) that will provide high-resolution optical imaging, as well near-infrared imaging spectroscopy, over about 14\,000\,deg$^2$ extragalactic sky. In addition to accurate weak lensing clustering measurements probe structure formation half age...
The Near-Infrared Spectrometer and Photometer (NISP) on board the Euclid satellite provides multiband photometry R>=450 slitless grism spectroscopy in 950-2020nm wavelength range. In this reference article we illuminate background of NISP's functional calibration requirements, describe instrument's integral components, provide all its key properties. We also sketch processes needed to understand how NISP operates is calibrated, technical potentials limitations. Links articles providing more...
The shortest distance around the Universe through us is unlikely to be much larger than horizon diameter if microwave background anomalies are due cosmic topology. We show that observational constraints from lack of matched temperature circles in leave many possibilities for such topologies. evaluate detectability multipole correlations sample cases. Searches topology signatures data over large space possible topologies pose a formidable computational challenge. Published by American...
Abstract If the Universe has non-trivial spatial topology, observables depend on both parameters of manifold and position orientation observer. In infinite Euclidean space, most cosmological arise from amplitudes Fourier modes primordial scalar curvature perturbations. Topological boundary conditions replace full set with specific linear combinations selected as eigenmodes Laplacian. We present formulas for in orientable manifolds topologies E 1 – 6 , 11 12 16 18 that encompass range...
Abstract The Universe is neither homogeneous nor isotropic, but it close enough that we can reasonably approximate as such on suitably large scales. inflationary-Λ-Cold Dark Matter (ΛCDM) concordance cosmology builds these assumptions to describe the origin and evolution of fluctuations. With standard about stress-energy sources, this system specified by just seven phenomenological parameters, whose precise relations underlying fundamental theories are complicated may depend details those...
The linear point (LP) standard ruler was identified as the basis of a purely geometric method for exploiting baryon acoustic oscillations (BAO). LP exploits BAO feature imprinted in galaxy two-point correlation function to measure cosmological distances independent any specific model. We forecast expected precision future and ongoing spectroscopic surveys leveraging point. investigate implications our forecasted results. focus particular on relevant working example: detection late-time...
A new computational scheme for the nonlinear cosmological matter power spectrum (PS) is presented. Our method based on evolution equations in time, which can be cast a form extremely convenient fast numerical evaluations. PS obtained time comparable to that needed simple 1-loop computation, and implementation very simple. results agree with N-body simulations at percent level BAO range of scales, few-percent up k ≃ 1 h/Mpc z≳0.5, thereby opening possibility applying this tool scales...
We present the latest version of Pinocchio, a code that generates catalogues DM haloes in an approximate but fast way with respect to N-body simulation. This extends computation particle and halo displacements up 3rd-order Lagrangian Perturbation Theory (LPT), contrast previous versions used Zeldovich approximation (ZA). run Pinocchio on same initial configuration reference simulation, so comparison object-by-object level. consider at redshifts 0 1, using different LPT orders either for...
Abstract Cosmic microwave background (CMB) temperature and polarization observations indicate that in the best-fit Λ Cold Dark Matter model of Universe, local geometry is consistent with at most a small amount positive or negative curvature, i.e., |Ω K | ≪ 1. However, whether flat ( E 3 ), positively curved S ) negatively H there are many possible topologies. Among topologies geometry, lens spaces L p , q where > 1 0 < integers, quotients covering space (the three-sphere) by ℤ cyclic...
Leveraging the Baryon Acoustic Oscillations (BAO) feature present in clustering 2-point statistics, we aim to measure cosmological distances independently of underlying background model. However this inference is complicated by late-time non-linearities that introduce model and tracer dependencies correlation function power spectrum, which must be properly accounted for. With mind, "Purely-Geometric-BAO," provides a rigorous tool without assuming specific cosmology. We focus on monopole,...
The linear point (LP), defined as the mid-point between dip and peak of two-point clustering correlation function (TPCF), has been shown to be an excellent standard ruler for cosmology. In fact, it is nearly redshift-independent, being weakly sensitive non-linearities, scale-dependent halo bias redshift-space distortions. So far, these findings were tested assuming that neutrinos are massless; in this paper we extend analysis massive-neutrino cosmologies. particular, examine if growth...
One of the nicest results in cosmological perturbation theory is analytical resummaton leading corrections at large momentum, which was obtained by Crocce and Scoccimarro for propagator. Using an exact evolution equation, we generalize this result, showing that a class next-to-leading can also be resummed all orders theory. The new modify propagator few percent Baryonic Acoustic Oscillation range scales, therefore cannot neglected resummation schemes aiming accuracy compatible with future...
The baryon acoustic oscillations feature (BAO) imprinted in the clustering correlation function is known to furnish us cosmic distance determinations that are independent of cosmological-background model and primordial perturbation parameters. These measurements can be accomplished rigorously by means purely geometric BAO methods. To date two different approaches have been proposed. first exploits linear-point standard ruler. second, called correlation-function model-fitting, sound-horizon A...
We consider a dark energy fluid with arbitrary sound speed and equation of state discuss the effect its clustering on cold matter distribution at non-linear level. write continuity, Euler Poisson equations for system in Newtonian approximation. Then, using time renormalization group method to resum perturbative corrections all orders, we compute total power spectrum spectrum. At linear level, different from that light modifies observationally interesting scales, such as those relevant...
We propose a new way of looking at the Baryon Acoustic Oscillation in large-scale-structure clustering correlation function. identify scale sLP that has two fundamental features: its position is insensitive to non-linear gravity, redshift-space distortions and scale-dependent bias 0.5 per cent level; it geometrical, i.e. independent power spectrum primordial density fluctuation parameters. These properties together make sLP, called 'linear point', an excellent cosmological standard ruler....
We show how a characteristic length scale imprinted in the galaxy two-point correlation function, dubbed "linear point," can serve as comoving cosmological standard ruler. In contrast to baryon acoustic oscillation peak location, this is constant redshift and unaffected by nonlinear effects within 0.5 percent precision. measure location of linear point function LOWZ CMASS samples from Twelfth Data Release (DR12) Baryon Oscillation Spectroscopic Survey (BOSS) Collaboration. combine our...
Non-trivial spatial topology of the Universe may give rise to potentially measurable signatures in cosmic microwave background. We explore different machine learning approaches classify harmonic-space realizations background test case Euclidean $E_1$ (the 3-torus) with a cubic fundamental domain size scale significantly smaller than diameter last scattering surface. This is first step toward developing approach classification and likelihood-free inference topological parameters. Different...
Abstract The standard cosmological model, which assumes statistical isotropy and parity invariance, predicts the absence of correlations between even-parity odd-parity observables cosmic microwave background (CMB). Contrary to these predictions, large-angle CMB temperature anomalies generically involve even- ℓ odd- angular power spectrum C , while recent analyses polarization have revealed non-zero equal- EB correlations. These findings challenge conventional understanding, suggesting...
Due to late-time nonlinearities, the location of acoustic peak in two-point galaxy correlation function is a redshift-dependent quantity, and thus it cannot be simply employed as cosmological standard ruler. This has motivated recent proposal novel ruler, also located baryon oscillation range scales function, dubbed linear point. Unlike peak, insensitive at 0.5% level many nonlinear effects that distort clustering shift peak. However, this not enough make point useful In addition, we require...
General Relativistic effects on the clustering of matter in universe provide a sensitive probe cosmology and gravity theories that can be tested with upcoming generation galaxy surveys. Here, we present suite large volume high-resolution N-body simulations specifically designed to generate light-cone data for study relativistic lensing-matter observables. RayGalGroupSims (or short RayGal) consists two $(2625\,h^{-1}\,{\rm Mpc})^3$ $4096^3$ particles standard flat $\Lambda$CDM model...
We extend the resummation method of Anselmi & Pietroni (2012) to compute total density power spectrum in models quintessence characterized by a vanishing speed sound. For standard ΛCDM cosmologies, this scheme allows predictions with an accuracy at few percent level beyond range scales where acoustic oscillations are present, therefore comparable other, common numerical tools. In addition, our theoretical approach indicates approximate but valuable and simple relation between spectra for...
This work focusses on the pilot run of a simulation campaign aimed at investigating spectroscopic capabilities Euclid Near-Infrared Spectrometer and Photometer (NISP), in terms continuum emission line detection context galaxy evolutionary studies. To this purpose, we constructed, emulated, analysed spectra 4992 star-forming galaxies 0.3 ≤ z 2.5 using NISP pixel-level simulator. We built spectral library starting from public multi-wavelength catalogues, with value-added information energy...