Discovery of black hole binaries by LIGO/Virgo provoked a renewed interest in primordial black holes (PBHs). After I give a brief introduction of PBHs, I explain how PBHs form binaries and compute their merger rate.

Cosmological inflation has been the main paradigm for early universe cosmology since the early 1980s, but we are still lacking an embedding of inflation into fundamental physics. I will discuss constraints on inflation, and on other scenarios of early universe cosmology, which arise when one tries to embed the scenarios into superstring theory.

Primordial black holes can be seeded by large cosmological fluctuations produced during inflation. This happens if the potential for inflation is sufficiently flat in some regions. However, in such regions, the dynamics of the inflaton is dominated by quantum diffusion rather than by classical slow roll. This implies that the standard method to calculate the amplitude of the fluctuations,...

Given a possibility that black holes detected by LIGO/Virgo are PBHs, a next direction we should proceed is to propose ideas for testing the PBH hypothesis. I will introduce my recent proposal that makes use of the mass distribution as well as other proposals.

In this talk I will discuss how to calculate the abundance of primordial black holes given an inflationary power spectrum

I will discuss the properties of the primordial power spectrum so that PBHs are produced in accordance with the constraints coming from the CMB and BBN observables. I will mainly focus on the large wavenumbers of the power spectrum where, if there is a peak, PBH with sub-solar masses are generated. Then I will describe the scenario that the dark matter in the universe is comprised either of...

The latest Planck’s analysis of the power spectrum finds 10% more lensing smoothing than predicted by LCDM at 2 sigma. If it is not a statistical fluke, it could indicate new physics that mimick the smoothing effect of lensing. What could that be and how was generated? First, I will show you that oscillations in the primordial power spectrum with the same frequency as the acoustic peaks but...