A5018930192- Cosmology and Gravitation Theories
- Pulsars and Gravitational Waves Research
- Geophysics and Gravity Measurements
- Black Holes and Theoretical Physics
- Dark Matter and Cosmic Phenomena
- Astronomy and Astrophysical Research
- Radio Astronomy Observations and Technology
- Astrophysics and Cosmic Phenomena
- Solar and Space Plasma Dynamics
- Galaxies: Formation, Evolution, Phenomena
- Stochastic processes and financial applications
- Scientific Research and Discoveries
- Experimental and Theoretical Physics Studies
- History and Developments in Astronomy
- Stellar, planetary, and galactic studies
- Relativity and Gravitational Theory
University of Amsterdam
2022-2024
Delta Institute for Theoretical Physics
2023
University of Sussex
2018-2021
We derive analytic bounds on the shape of primordial power spectrum in context single-field inflation. In particular, steepest possible growth has a spectral index $n_s - 1 = 4$ once transients have died down. Its primary implication is that any constraint at particular scale can be extrapolated to an upper bound over extended range scales. This important for models which generate relics due enhanced amplitude scalar perturbations, such as black holes. order them, needs grow many orders...
We compare primordial black hole (PBH) constraints on the power spectrum and mass distributions using traditional Press Schechter formalism, peaks theory, a recently developed version of theory relevant to PBHs. show that, provided PBH formation criteria smoothing are treated consistently, only vary by ∼ 10% between methods (a difference that will become increasingly important with better data). Our robust from PBHs take into account effects critical collapse, non-linear relation ζ δ, shift...
All single-field inflationary models invoke varying degrees of tuning in order to account for cosmological observations. Mechanisms that generate primordial black holes (PBHs) from enhancement power at small scales posit potentials transiently break scale invariance and possibly adiabaticity over a range modes. This requires additional on top required observations probed by cosmic microwave background (CMB) anisotropies. In this paper we study the parametric dependence various inflation...
Future ground-based gravitational wave observatories will be ideal probes of the environments surrounding black holes with masses $1\ensuremath{-}10{M}_{\ensuremath{\bigodot}}$. Binary hole mergers mass ratios order $q={m}_{2}/{m}_{1}\ensuremath{\lesssim}{10}^{\ensuremath{-}3}$ can remain in frequency band such detectors for months or years, enabling precision searches modifications their waveforms respect to vacuum inspirals. As a concrete example an environmental effect, we consider here...
Exploring dark matter via observations of extreme astrophysical environments -- defined here as heavy compact objects such white dwarfs, neutron stars, and black holes, well supernovae object merger events has been a major field growth since the last Snowmass process. Theoretical work highlighted utility current near-future observatories to constrain novel parameter space across full mass range. This includes gravitational wave instruments spanning electromagnetic spectrum, from radio...
Abstract Primordial black holes (PBHs) can be produced by a range of mechanisms in the early universe. A particular formation channel that connects PBHs with inflationary phenomenology invokes enhanced primordial curvature perturbations at small scales. In this paper, we examine how rapidly background transition between different values parameters Hubble hierarchy context single-clock inflation, which must ultimately derive from consistent derivative expansion for inflaton field. We discuss...
Following the pioneering observations with COBE in early 1990s, studies of cosmic microwave background (CMB) have focused on temperature and polarization anisotropies. CMB spectral distortions - tiny departures energy spectrum from that a perfect blackbody provide second, independent probe fundamental physics, reach deep into primordial Universe. The theoretical foundation has seen major advances recent years, which highlight immense potential this emerging field. Spectral property Universe...
Observational constraints on the abundance of primordial black holes (PBHs) constrain allowed amplitude power spectrum both smallest and largest ranges scales, covering over 20 decades from 1−1020/ Mpc. Despite tight fraction PBHs at their time formation near horizon entry in early Universe, corresponding are quite weak, typically R≲ 10−2 assuming Gaussian perturbations. Motivated by recent claims that evaporation just one PBH would destabilise Higgs vacuum collapse we calculate which follow...
Primordial black holes (PBHs) can be produced by a range of mechanisms in the early universe. A particular formation channel that connects PBHs with inflationary phenomenology invokes enhanced primordial curvature perturbations at small scales. In this paper, we examine how rapidly background transition between different values parameters Hubble hierarchy context single-clock inflation, which must ultimately derive from consistent derivative expansion for inflaton field. We discuss artefacts...
The LIGO discoveries have rekindled suggestions that primordial black holes (BHs) may constitute part to all of the dark matter (DM) in Universe. Such came from 1) observed merger rate BHs, 2) their unusual masses, 3) low/zero spins, and 4) also independently uncovered cosmic infrared background (CIB) fluctuations signal high amplitude coherence with unresolved X-ray (CXB). Here we summarize prospects resolve this important issue electromagnetic observations using instruments tools expected...
Primordial black hole production in the mass range $10-10^4 \,{\rm M_\odot}$ is motivated respectively by interpretations of LIGO/Virgo observations binary mergers and their ability to seed intermediate holes which would account for presence supermassive at very high redshift. Their existence imply a boost primordial power spectrum if they were produced overdensities reentering horizon collapsing after single-field inflation. This, together with associated Poisson fluctuations cause matter...
Future gravitational wave interferometers such as LISA, Taiji, DECIGO, and TianQin, will enable precision studies of the environment surrounding black holes. In this paper, we study intermediate extreme mass ratio binary hole inspirals, consider three possible environments primary hole: accretion disks, dark matter spikes, clouds ultra-light scalar fields, also known atoms. We present a Bayesian analysis detectability measurability these environments. Focusing for concreteness on case...
These lecture notes are based on those presented at the Theoretical Aspects of Astroparticle Physics, Cosmology and Gravitation School Galileo Galilee Institute in Florence 2021, https://agenda.infn.it/event/24368/. They aim to provide a pedagogical introduction basic working knowledge single-field inflation including ultra-slow-roll regime, where perturbations grow exponentially. This rapid growth is connected formation primordial black holes (PBHs), special dark matter candidate probe...
It is possible that a multi-component dark matter model required if primordial black holes only contribute to fraction of the energy density in matter. This increasingly more likely with respect case $f_{\rm PBH} = 1$, since there one remaining window, on asteroid-mass scales, where can make up all A mixed lead interesting observables come about due interactions between and second component. provide unique signatures presence increase prospects detection or improvement constraints mass...
All single-field inflationary models invoke varying degrees of tuning in order to account for cosmological observations. Mechanisms that generate primordial black holes (PBHs) from enhancement power at small scales posit potentials transiently break scale invariance and possibly adiabaticity over a range modes. This requires additional on top required observations probed by cosmic microwave background (CMB) anisotropies. In this paper we study the parametric dependence various inflation...
Future ground-based gravitational wave observatories will be ideal probes of the environments surrounding black holes with masses $1 - 10\,\mathrm{M_\odot}$. Binary hole mergers mass ratios order $q=m_2/m_1\lesssim10^{-3}$ can remain in frequency band such detectors for months or years, enabling precision searches modifications their waveforms respect to vacuum inspirals. As a concrete example an environmental effect, we consider here population binary primordial which are expected embedded...