A5016911084- Pulsars and Gravitational Waves Research
- Cosmology and Gravitation Theories
- Black Holes and Theoretical Physics
- Astrophysical Phenomena and Observations
- Geophysics and Gravity Measurements
- Gamma-ray bursts and supernovae
- Relativity and Gravitational Theory
- Geophysics and Sensor Technology
- Astrophysics and Cosmic Phenomena
- Dark Matter and Cosmic Phenomena
- Quantum Electrodynamics and Casimir Effect
- Atomic and Subatomic Physics Research
- Radio Astronomy Observations and Technology
- High-pressure geophysics and materials
- Solar and Space Plasma Dynamics
- Noncommutative and Quantum Gravity Theories
- Galaxies: Formation, Evolution, Phenomena
- Advanced Differential Geometry Research
- Cold Atom Physics and Bose-Einstein Condensates
- Particle physics theoretical and experimental studies
- Stellar, planetary, and galactic studies
- Elasticity and Material Modeling
- Computational Physics and Python Applications
- Superconducting Materials and Applications
- Seismic Waves and Analysis
Istituto Nazionale di Fisica Nucleare, Sezione di Roma I
2016-2025
Sapienza University of Rome
2016-2025
Laboratoire AstroParticule et Cosmologie
2024
Tecnologie Avanzate (Italy)
2019-2020
King's College London
2019
University of Lisbon
2011-2017
Perimeter Institute
2014-2017
Instituto Superior Técnico
2009-2015
Center for Astrophysics Harvard & Smithsonian
2013-2015
Instituto Politécnico de Lisboa
2015
One century after its formulation, Einstein's general relativity (GR) has made remarkable predictions and turned out to be compatible with all experimental tests. Most of these tests probe the theory in weak-field regime, there are theoretical reasons believe that GR should modified when gravitational fields strong spacetime curvature is large. The best astrophysical laboratories strong-field gravity black holes neutron stars, whether isolated or binary systems. We review motivations...
Very compact objects probe extreme gravitational fields and may be the key to understand outstanding puzzles in fundamental physics. These include nature of dark matter, fate spacetime singularities, or loss unitarity Hawking evaporation. The standard astrophysical description collapsing tells us that massive, are black holes. Any observation suggesting otherwise would an indication beyond-the-standard-model Null results strengthen quantify Kerr hole paradigm. advent gravitational-wave...
It is commonly believed that the ringdown signal from a binary coalescence provides conclusive proof for formation of an event horizon after merger. This expectation based on assumption waveform at intermediate times dominated by quasinormal modes final object. We point out this should be taken with great care, and very compact objects light ring will display similar stage, even when their quasinormal-mode spectrum completely different black hole. In other words, universal waveforms indicate...
Gravitational waves from binary coalescences provide one of the cleanest signatures nature compact objects. It has been recently argued that post-merger ringdown waveform exotic ultracompact objects is initially identical to a black-hole, and putative corrections at horizon scale will appear as secondary pulses after main burst radiation. Here we extend this analysis in three important directions: (i) show result applies large class with photon sphere for generic orbits test-particle limit;...
[abridged abstract] No, within a broad class of scenarios. With the advent gravitational-wave (GW) astronomy, environmental effects on GW signal will eventually have to be quantified. Here we present wide survey corrections due these in two situations great interest for astronomy: black hole (BH) ringdown emission and inspiral compact objects. We take into account various such as: electric charges, magnetic fields, cosmological evolution, possible deviations from General Relativity,...
Ultralight bosons can induce superradiant instabilities in spinning black holes, tapping their rotational energy to trigger the growth of a bosonic condensate. Possible observational imprints these boson clouds include (i) direct detection nearly monochromatic (resolvable or stochastic) gravitational waves emitted by condensate, and (ii) statistically significant evidence for formation "holes" at large spins spin versus mass plane (sometimes also referred as "Regge plane") astrophysical...
The grand challenges of contemporary fundamental physics---dark matter, dark energy, vacuum inflation and early universe cosmology, singularities the hierarchy problem---all involve gravity as a key component. And all gravitational phenomena, black holes stand out in their elegant simplicity, while harbouring some most remarkable predictions General Relativity: event horizons, ergoregions. hitherto invisible landscape Universe is being unveiled before our eyes: historical direct detection...
Massive bosonic fields of arbitrary spin are predicted by general extensions the Standard Model. It has been recently shown that there exists a family bimetric theories gravity - including massive which free Boulware-Deser ghosts at nonlinear level. This opens up possibility to describe consistently dynamics spin-2 particles in gravitational field. Within this context, we develop study fluctuations gravitons around Schwarzschild and slowly-rotating Kerr black holes. Our work two important...
Superradiant instabilities of spinning black holes can be used to impose strong constraints on ultralight bosons, thus turning into effective particle detectors. However, very little is known about the development instability and whether its nonlinear time evolution accords linear intuition. For first time, we attack this problem by studying impact gravitational-wave emission gas accretion instability. Our quasi-adiabatic, fully-relativistic analysis shows that: (i) does not have a...
Ultracompact objects are self-gravitating systems with a light ring. It was recently suggested that fluctuations in the background of these extremely long lived and might turn unstable at nonlinear level, if object is not endowed horizon. If correct, this result has important consequences: ring black holes. In other words, instability ultracompact stars would provide strong argument favor ``black hole hypothesis,'' once electromagnetic or gravitational-wave observations confirm existence...
The tidal Love numbers (TLNs) encode the deformability of a self-gravitating object immersed in environment and depend significantly both on object's internal structure dynamics gravitational field. An intriguing result classical general relativity is vanishing TLNs black holes. We extend this three ways, aiming at testing nature compact objects: (i) we compute exotic objects, including different families boson stars, gravastars, wormholes, other toy models for quantum corrections horizon...
Generic extensions of the standard model predict existence ultralight bosonic degrees freedom. Several ongoing experiments are aimed at detecting these particles or constraining their mass range. Here we show that massive vector fields around rotating black holes can give rise to a strong superradiant instability, which extracts angular momentum from hole. The observation supermassive spinning imposes limits on this mechanism. We current black-hole spin estimates provide tightest upper...
Abstract The Einstein Telescope (ET), the European project for a third-generation gravitational-wave detector, has reference configuration based on triangular shape consisting of three nested detectors with 10 km arms, where each detector 'xylophone' made an interferometer tuned toward high frequencies, and low frequencies working at cryogenic temperature. Here, we examine scientific perspectives under possible variations this design. We perform detailed evaluation science case single...
Gravitational waves emitted by distorted black holes---such as those arising from the coalescence of two neutron stars or holes---carry not only information about corresponding spacetime but also underlying theory gravity. Although general relativity remains simplest, most elegant, and viable gravitation, there are generic robust arguments indicating that it is ultimate description gravitational universe. Here, we focus on a particularly appealing extension relativity, which corrects...
Ultralight scalar fields around spinning black holes can trigger superradiant instabilities, forming a long-lived bosonic condensate outside the horizon. We use numerical solutions of perturbed field equations and astrophysical models massive stellar-mass hole populations to compute, for first time, stochastic gravitational-wave background from these sources. In optimistic scenarios is observable by Advanced LIGO LISA masses $m_s$ in range $\sim [2\times 10^{-13}, 10^{-12}]\,{\rm eV}$...
The Laser Interferometer Space Antenna (LISA) has the potential to reveal wonders about fundamental theory of nature at play in extreme gravity regime, where gravitational interaction is both strong and dynamical. In this white paper, Fundamental Physics Working Group LISA Consortium summarizes current topics physics observations GWs can be expected provide key input. We briefest reviews then delineate avenues for future research directions discuss connections between working group, other...
We study the nonlinear dynamics of black holes that carry scalar hair and binaries composed such holes. The is due to a linear or exponential coupling between Gauss-Bonnet invariant. work perturbatively in constant interaction but nonperturbatively fields. first consider dynamical formation for isolated arbitrary spin determine final state. This also allows us compute time quasinormal modes rotating presence this coupling. then evolution nonspinning hole with various mass ratios produce...
The LIGO and Virgo Interferometers have so far provided 11 gravitational-wave (GW) observations of black-hole binaries. Similar detections are bound to become very frequent in the near future. With current upcoming wealth data, it is possible confront specific formation models with observations. We investigate here whether data compatible hypothesis that LIGO/Virgo black holes primordial origin. compute detail mass spin distributions (PBHs), their merger rates, stochastic background...
The LIGO/Virgo Collaboration has recently observed GW190521, the first binary black hole merger with at least primary component mass in gap predicted by pair-instability supernova theory. This observation disfavors standard stellar-origin formation scenario for heavier hole, motivating alternative hypotheses. We show that GW190521 cannot be explained within primordial (PBH) if PBHs do not accrete during their cosmological evolution, since this would require an abundance which is already...
With several dozen binary black hole events detected by LIGO-Virgo to date and many more expected in the next few years, gravitational-wave astronomy is shifting from individual-event analyses population studies. Using GWTC-2 catalog, we perform a hierarchical Bayesian analysis that for first time combines state-of-the-art astrophysical formation models with of primordial holes (PBHs) constrains fraction putative subpopulation PBHs data. We find this depends significantly on set assumed...
Primordial black holes (PBHs) might be formed in the early Universe and could comprise at least a fraction of dark matter. Using recently released GWTC-2 dataset from third observing run LIGO-Virgo Collaboration, we investigate whether current observations are compatible with hypothesis that all hole mergers detected so far primordial origin. We constrain PBH formation models within hierarchical Bayesian inference framework based on deep learning techniques, finding best-fit values for...
We perform a hierarchical Bayesian analysis of the GWTC-2 catalog to investigate mixed scenario in which merger events are explained by black holes both astrophysical and primordial origin. For we adopt phenomenological model used LIGO/Virgo collaboration include correlation between different parameters inferred from data, role spins scenarios, impact accretion scenario. Our best-fit has strong statistical evidence relative single-population model, thus supporting coexistence populations...