Related papers: Early inflation based on an aboriginal black hole
Model independent arguments following from the Covariant Entropy Principle imply that causal diamonds in the very early universe were entirely filled with a single equilibrated system with finite entropy. A universe where this condition…
Primordial black holes may owe their origin to the small-scale enhancement of the comoving curvature perturbation generated during inflation. Their mass fraction at formation is markedly sensitive to possible non-Gaussianities in such…
Trapped inflation has been proposed to provide a successful inflation with a steep potential. We discuss the formation of primordial black holes in the trapped inflationary scenario. We show that primordial black holes are naturally…
Using a new kind of 5D Ricci-flat canonical metric, we obtain by a static foliation an effective 4D Schwarzschild-de Sitter hypersurface. We examine some particular initial conditions which could be responsible for the inflationary…
Primordial black holes (PBH) may form from large cosmological perturbations, produced during inflation when the inflaton's velocity is sufficiently slowed down. This usually requires very flat regions in the inflationary potential. In this…
In response to a recent criticism, appeared in arXiv:2303.00341, we argue that the standard scenario to form primordial black holes in the early universe based on a phase of ultra-slow-roll in single-field inflation is not ruled out.
We show that holographic dark energy could explain why the current dark energy density is so small, if there was an inflation with a sufficient expansion in the early universe. It is also suggested that an inflation with the number of…
In this work we have investigated the inflation mechanism driven by the Barrow Holographic dark energy (BHDE) in the early universe. BHDE is based on the Barrow relation for horizon entropy, which in turn is inspired from the shape of the…
We propose a new mechanism of primordial black hole formation via an interrupted phase transition during the early matter-dominated stage of reheating after inflation. In reheating, induced by the decay of a pressureless fluid dominating…
It is well known that a primordial black hole (PBH) can be generated in the inflation process of the early universe, especially when the inflation field has a number of non-trivial features that could break the slow-roll condition. In this…
We study a double inflation model (a preinflation + a new inflation) in supergravity and discuss the formation of primordial black holes which may be identified with massive compact halo objects (MACHOs) observed in the halo of our galaxy.…
The primordial black hole (PBH) productions from the inflationary potential with an inflection point usually rely heavily on the fine-tuning of the model parameters. We propose in this work a new kind of the $\alpha$-attractor inflation…
We propose a new single field inflation model in which the usual slow-roll inflation is joined to a new period of slow-climb and slow-roll inflation through a short intermediate non-inflationary phase. We then show that primordial curvature…
Using ideas of STM theory, but starting from a 6D vacuum state, we propose an inflationary model where the universe emerges from the blast of a white hole. Under this approach, the expansion is affected by a geometrical deformation induced…
We discuss the model of the primordial black holes formation at the reheating stage. These small massive black holes appear due to specific properties of the compact extra dimensions. The latter gives rise the low energy model containing…
We investigate the evolution of black holes present during the inflationary epoch, assuming they are dynamically coupled to the cosmological background through a generalized McVittie geometry, such that their gravitational mass scales with…
It has been recently pointed out that the initial value problem in new inflation models is naturally solved by supergravity effects if there exists a pre-inflation before the new inflation. We study this double inflation model in details…
The inflationary phase of the Universe is explored by proposing a toy model related to the scalar field, termed as {\it inflaton}. The potential part of the energy density in the said era is assumed to have a constant vacuum energy density…
A mechanism of inflation from higher dimensions compactification is studied. An Early Universe capable of providing exponential growth for some dimensions and exponential contraction for others, giving therefore an explanation for the big…
Primordial black holes may form in the early Universe, for example from the collapse of large amplitude density perturbations predicted in some inflationary models. Light black holes undergo Hawking evaporation, the energy injection from…