Conveners
Effects of Primordial Perturbations Enhancement: from Black Holes Formation to CMB Anomalies: Block 1
- Krzysztof Turzynski (University of Warsaw, Faculty of Physics)
- Antonio Enea Romano (UDEA/CERN)
Description
There are several important phenomena associated to the enhancement of primordial perturbation, such as the production of primordial black holes (PBH), or local modifications of the cosmic microwave background (CMB) spectrum. General model-independent considerations suggest two main mechanisms which can lead to the enhancement: a temporary violation of the slow-roll conditions during inflation, or the presence of large primordial non adiabatic or anisotropic perturbations.
In this section, we will focus on the different theoretical scenarios proposed to produce the perturbations enhancement, on its observational effects on PBHs and CMB, and on the advantages of adopting a model independent approach. In the context of PBHs, special attention will be devoted to the numerical simulations of the PBHs formation, and to the effects of the shape of the peaks of perturbations. We also invite all other theoretical ideas about the enhancement of primordial perturbations and PBH production originating from inflationary or post-inflationary dynamics.
Primordial Black Holes (PBHs) have entered the forefront of theoretical cosmology, due their potential role in phenomena ranging from gravitational waves, to dark matter, to galaxy formation. While producing PBHs from inflationary fluctuations naively would seem to require a large deceleration of the inflaton from its velocity at the horizon exit of CMB scales, in this talk we demonstrate that...
In this talk, I will talk about the recent developments in numerical simulations of PBHs under spherical symmetry on a FRW background. Specifically, I will focus on the threshold for PBH formation and the effect of the accretion and sizes of the PBHs formed in terms of the specific shape of the initial curvature profile.
The enhancement of the spectrum of primordial comoving curvature perturbation $\mathcal{R}$ can induce the production of primordial black holes (PBH) which could account for part of present day dark matter.
As an example of the effects of the modification of gravity on the production of PBHs, we investigate the effects on the spectrum of $\mathcal{R}$ produced by the modification of gravity...
The LIGO-Virgo Collaboration has so far detected around 90 black holes, some of which have masses larger than what were expected from the collapse of stars. The mass distribution of LIGO-Virgo black holes appears to have a peak at ∼ $30M_\odot$ and two tails on the ends. By assuming that they all have a primordial origin, we analyze the GWTC-1 (O1&O2) and GWTC-2 (O3a) datasets by performing...
Detection of gravitational waves (GW) from compact binary mergers provide a new window into multi-messenger astrophysics. The standard technique to determine the merger parameters is matched filtering, consisting in comparing the signal to a template bank. This approach can be time consuming and computationally expensive due to the large amount of experimental data which needs to be analyzed....
The paradigm of slow-roll inflation provides a snapshot of the early universe that is in good agreement with present observations. Despite its success, most of the models studied so far rely heavily on the assumption that the universe is perfectly isotropic at early times. In this talk, I will discuss recent advances in anisotropic inflationary models. We adopt a Fock quantization for...
We show that in absence of entropy or effective anisotropic stress the freedom in the choice of the initial energy scale of inflation implies the existence of an infinite family of dual slow-roll parameters histories which can produce the same spectrum of comoving curvature perturbations. This implies that in general there is no one-to-one correspondence between the spectrum and higher order...
Small scale CMB data contain a lot of cosmological information hidden in the different components : primordial CMB, tSZ effect, kSZ effect, CIB. Standard analyses assume templates for non primordial CMB components and lose the cosmological signature of large scale structures contained in secondary anisotropies. I will present a new analysis of SPT data at small scales where the tSZ spectrum is...
