On primordial black holes from rapid turns in two-field models

  title={On primordial black holes from rapid turns in two-field models},
  author={Lilia Anguelova},
  journal={Journal of Cosmology and Astroparticle Physics},
  • L. Anguelova
  • Published 7 December 2020
  • Physics
  • Journal of Cosmology and Astroparticle Physics
We study rapid-turn trajectories in a class of two-field cosmological models, whose scalar manifold is the Poincaré disk. Background solutions in multi-field inflation, with field-space trajectories exhibiting sharp turns, can seed primordial black hole (PBH) formation. We investigate a class of exact solutions with hidden symmetry and show that they exhibit the kind of transient rapid-turn period, needed to induce PBH generation. Furthermore, we relax the symmetry condition and find, in a… 

Double monodromy inflation: Gravitational wave factory for CMB-S4, LiteBIRD, and LISA

We consider a short rollercoaster cosmology based on two stages of monodromy inflation separated by a stage of matter domination, generated after the early inflaton falls out of slow roll. If the

Mechanisms of producing primordial black holes by breaking the SU(2, 1)/SU(2)×U(1) symmetry

In this paper we present a class of potentials derived by no-scale supergravity in order to explain the production of primordial black holes (PBHs) in the Universe. By breaking the SU(2,1)/SU(2)×U(1)

Dark energy from inspiraling in field space

We find an exact solution of the equations of motion of a two-field cosmological model, which realizes multi-field dark energy. The latter is characterized by field-space trajectories with turning

Sharp turns in axion monodromy: primordial black holes and gravitational waves

: Large and sharp turns in multifield inflation can lead to a very rich phenomenology, but are difficult to realise in supergravity, and typically require large field space curvatures. In this work, we

Dilaton-axion inflation with PBHs and GWs

We discuss two-stage dilaton-axion inflation models [1] and describe α-attractor models with either exponential or polynomial approach to the plateau. We implement one of the models of primordial

Dynamical renormalization and universality in classical multifield cosmological models

Primordial gravitational waves from excited states

We show that a scalar excited state with large occupation numbers during inflation leads to an enhancement of tensor modes and a characteristic pattern of order-one oscillations in the associated

Rapid-turn inflation in supergravity is rare and tachyonic

Strongly non-geodesic, or rapidly turning trajectories in multifield inflation have attracted much interest recently from both theoretical and phenomenological perspectives. Most models with large



Turning in the landscape: a new mechanism for generating Primordial Black Holes

We propose a new model-independent mechanism for producing Primordial Black Holes from a period of multi-field inflation. The required enhancement of primordial fluctuations compared to their value

Primordial black holes from modified supergravity

The modified supergravity approach is applied to describe a formation of Primordial Black Holes (PBHs) after Starobinsky inflation. Our approach naturally leads to the two-(scalar)-field

Primordial perturbations from inflation with a hyperbolic field-space

We study primordial perturbations from hyperinflation, proposed recently and based on a hyperbolic field-space. In the previous work, it was shown that the field-space angular momentum supported by

Seeding Primordial Black Holes in Multifield Inflation.

It is shown that isocurvature fluctuations can mix with ζ inducing large enhancements of its amplitude, and that the large enhancements required for PBHs demand noncanonical kinetic terms in the action of the multifield system.

Mild non-Gaussianities under perturbative control from rapid-turn inflation models

Inflation can be supported in very steep potentials if it is generated by rapidly turning fields, which can be natural in negatively curved field spaces. The curvature perturbation, ζ, of these

The multi-field, rapid-turn inflationary solution

There are well-known criteria on the potential and field-space geometry for determining if slow-roll, slow-turn, multi-field inflation is possible. However, even though it has been a topic of much

Primordial black holes from α-attractors

We consider primordial black hole (PBH) production in inflationary α-attractors. We discuss two classes of models, namely models with a minimal polynomial superpotential as well as modulated chaotic

Single field double inflation and primordial black holes

Within the framework of scalar-tensor theories, we study the conditions that allow single field inflation dynamics on small cosmological scales to significantly differ from that of the large scales

Perturbations in generalized multi-field inflation

We study the linear perturbations of multi-field inflationary models governed by a Lagrangian which is a general function of the scalar fields and of a global kinetic term combining their spacetime

Primordial black hole dark matter in dilaton-extended two-field Starobinsky inflation

We investigate the production of primordial black holes and their contribution to the presently observed dark matter in a dilaton two-field extension of Starobinsky's quadratic $f(R)$ model of