A5002247498- Cosmology and Gravitation Theories
- Galaxies: Formation, Evolution, Phenomena
- Black Holes and Theoretical Physics
- Geophysics and Gravity Measurements
- Radio Astronomy Observations and Technology
- Dark Matter and Cosmic Phenomena
- Pulsars and Gravitational Waves Research
- Solar and Space Plasma Dynamics
- Astronomy and Astrophysical Research
- Astrophysics and Cosmic Phenomena
- Stellar, planetary, and galactic studies
- Particle physics theoretical and experimental studies
- Gamma-ray bursts and supernovae
- Advanced Differential Geometry Research
- Noncommutative and Quantum Gravity Theories
- Particle Detector Development and Performance
- Scientific Research and Discoveries
- Computational Physics and Python Applications
- Neutrino Physics Research
- Adaptive optics and wavefront sensing
Istituto Nazionale di Fisica Nucleare, Sezione di Trieste
2023-2024
Istituto Nazionale di Fisica Nucleare
2023-2024
Scuola Internazionale Superiore di Studi Avanzati
2023-2024
Institute for Fundamental Physics of the Universe
2023-2024
University of Geneva
2021-2023
Centre de Recerca Matemàtica
2023
University of Oxford
2017-2021
Universitat de Barcelona
2015-2018
Heidelberg University
2013-2014
University of Padua
2010-2013
The detection of an electromagnetic counterpart (GRB 170817A) to the gravitational-wave signal (GW170817) from merger two neutron stars opens a completely new arena for testing theories gravity. We show that this measurement allows us place stringent constraints on general scalar-tensor and vector-tensor theories, while allowing independent bound graviton mass in bimetric These severely reduce viable range cosmological models have been proposed as alternatives relativistic cosmology.Received...
We present a turnkey solution, ready for implementation in numerical codes, the study of linear structure formation general scalar-tensor models involving single universally coupled scalar field. show that totality cosmological information on gravitational sector can be compressed - without any redundancy into five independent and arbitrary functions time only one constant. These describe physical properties universe: observable background expansion history, fractional matter density today,...
We present the public version of hi_class (www.hiclass-code.net), an extension Boltzmann code CLASS to a broad ensemble modifications general relativity. In particular, can calculate predictions for models based on Horndeski's theory, which is most scalar-tensor theory described by second-order equations motion and encompasses any perfect-fluid dark energy, quintessence, Brans-Dicke, f(R) covariant Galileon models. has been thoroughly tested be readily used understand impact alternative...
We investigate the limits of applicability quasistatic approximation in cosmologies featuring general models dark energy or modified gravity. show that, at best, breaks down outside sound horizon dark-energy, rather than cosmological as is frequently assumed. When speed significantly below that light, limit only valid a limited range observable scales and this must be taken into account when computing effects on observations such models. As an order magnitude estimate, analysis data from...
The next generation of surveys will greatly improve our knowledge cosmological gravity. In this paper we focus on how Stage IV photometric redshift surveys, including weak lensing and multiple tracers the matter distribution radio experiments combined with measurements cosmic microwave background lead to precision constraints deviations from general relativity. We use a broad subclass Horndeski scalar-tensor theories forecast accuracy which be able determine these their degeneracies other...
Recent anomalies found in cosmological datasets such as the low multipoles of Cosmic Microwave Background or redshift amplitude and growth clustering measured by e.g., abundance galaxy clusters space distortions surveys, have motivated explorations models beyond standard $\Lambda$CDM. Of particular interest are where general relativity (GR) is modified on large scales. Here we consider deviations from $\Lambda$CDM+GR within context Horndeski gravity, which most theory gravity with second...
In order to investigate the origin of ongoing tension between amplitude matter fluctuations measured by weak lensing experiments at low redshifts and value inferred from cosmic microwave background anisotropies, we reconstruct evolution this z ∼ 2 using existing large-scale structure data. To do so, decouple linear growth density inhomogeneities expansion, constrain its redshift dependence making use a combination 6 different data sets, including shear, galaxy clustering CMB lensing. We...
The disconnected part of the power spectrum covariance matrix (also known as "Gaussian" covariance) is dominant contribution on large scales for galaxy clustering and weak lensing datasets. presence a complicated sky mask causes non-trivial correlations between different Fourier/harmonic modes, which must be accurately characterized in order to obtain reliable cosmological constraints. This particularly relevant survey data. Unfortunately, an exact calculation these involves $O(\ell_{\rm...
We compare Einstein-Boltzmann solvers that include modifications to general relativity and find that, for a wide range of models parameters, they agree high level precision. look at three purpose codes primarily model scalar-tensor theories, Jordan-Brans-Dicke (JBD) gravity, code $f(R)$ covariant Galileons, Ho\ifmmode \check{r}\else \v{r}\fi{}ava-Lifschitz two nonlocal gravity. Comparing predictions the angular power spectrum cosmic microwave background dark matter suite different models, we...
We present a detailed study of second-order matter perturbations for the general Horn- deski class models. Being most scalar-tensor theory having equations motion, it includes many known gravity and dark energy theories General Relativity with cosmological constant as specific case. This enables us to estimate leading order bispectrum generated at late-times by gravitational instability. parametrize evolution first motion proposed Bellini Sawicki (2014), where free functions are assumed be...
Cosmological datasets have great potential to elucidate the nature of dark energy and test gravity on largest scales available observation. Theoretical predictions can be computed with hi_class (www.hiclass-code.net), an accurate, fast flexible code for linear cosmology, incorporating a wide range theories modifications general relativity. We introduce three new functionalities into hi_class: (1) Support models based covariant Lagrangians, including constraint-preserving integration scheme...
Astroparticle physics is undergoing a profound transformation, due to series of extraordinary new results, such as the discovery high-energy cosmic neutrinos with IceCube, direct detection gravitational waves LIGO and Virgo, many others. This white paper result collaborative effort that involved hundreds theoretical astroparticle physicists cosmologists, under coordination European Consortium for Theory (EuCAPT). Addressed whole community, it explores upcoming opportunities challenges our...
Context . The future Euclid space satellite mission will offer an invaluable opportunity to constrain modifications Einstein’s general relativity at cosmic scales. In this paper, we focus on modified gravity models characterised, linear scales, by a scale-independent growth of perturbations while featuring different testable types derivative screening mechanisms smaller non-linear Aims We considered three specific models, namely Jordan-Brans-Dicke, scalar-tensor theory with flat potential,...
In this paper we obtain the bispectrum of dark matter density perturbations in frame covariant cubic Galileon theories. This result is obtained by means a semi-analytic approach to second-order cosmologies, assuming Gaussian initial conditions. particular, show that, even presence large deviations linear growth-rate w.r.t. ΛCDM one, at level such are reduced few percent.
The physics case and an experimental overview of the MOLLER (Measurement Of a Lepton Electroweak Reaction) experiment at 12 GeV upgraded Jefferson Lab are presented. A highlight Fundamental Symmetries subfield 2007 NSAC Long Range Plan was SLAC E158 measurement parity-violating asymmetry $A_{PV}$ in polarized electron-electron (M{\o}ller) scattering. proposed will improve on this result by factor five, yielding most precise weak mixing angle low or high energy anticipated over next decade....
Attempts at constraining theories of late time accelerated expansion often assume broad priors for the parameters in their phenomenological description. Focusing on shift-symmetric scalar-tensor with standard gravitational wave speed, we show how a more careful analysis dynamical evolution leads to much narrower priors. In doing so, propose simple and accurate parametrization these theories, capturing redshift dependence equation state, $w(z)$, kinetic braiding parameter,...
Gravitational waves (GWs) emitted by binary sources are interesting signals for testing gravity on cosmological scales since they allow measurements of the luminosity distance. When followed electromagnetic counterparts, in particular, enable a reconstruction GW-distance-redshift relation. In context several modified (MG) theories, even when requiring that speed propagation is equal to light, this GW distance differs from standard due presence friction propagation. The very same source...
Cosmological observables show a dependence with the neutrino mass, which is partially degenerate parameters of extended models gravity. We study and explore this degeneracy in Horndeski generalized scalar-tensor theories Using forecasted cosmic microwave background galaxy power spectrum datasets, we find that single parameter linear regime effective theory dominates correlation total mass. For any given particular value approximately cancels suppression due to mass at redshift. The extent...
We analyse cosmological perturbations around a homogeneous and isotropic background for scalar-tensor, vector-tensor bimetric theories of gravity. Building on previous results, we propose unified view the effective parameters all these theories. Based this structure, explore viable space each family models by imposing absence ghosts gradient instabilities. then focus quasistatic regime confirm that can be approximated phenomenological two-parameter model described an Newton's constant...
We measure the harmonic-space auto-power spectrum of galaxy overdensity in LOFAR Two-metre Sky Survey (LoTSS) First Data Release and its cross correlation with map lensing convergence cosmic microwave background (CMB) from Planck collaboration. report a $\sim5\sigma$ detection cross-correlation. show that combination clustering power CMB cross-correlation allows us to place constraints on high-redshift tail redshift distribution, one largest sources uncertainty use continuum surveys for...
The scale of baryon acoustic oscillations (BAO) imprinted in the matter power spectrum provides an almost-perfect standard ruler: it only suffers subpercent deviations from fixed comoving length due to nonlinear effects. We study BAO shift large Horndeski class gravitational theories and compute its magnitude momentum space using second-order perturbation theory a peak-background split. prediction is affected by modified linear growth, as well effects that alter mode-coupling kernel. For...