A symmetric DBI action theory and its applications to inflationary cosmology

The Dirac-Born-Infeld (DBI) field theory in string theory is important and can provide the field of the universe’s inflation. At the same time, it provides a causal mechanism for generating the original density perturbation, thereby providing the necessary density perturbation for existing the dense and sparse matter distributions of the universe. We deduce a symmetric DBI action, introduce it into inflationary cosmology to calculate various inflation parameters, further calculate the scalar perturbation spectrum and the tensor-scalar ratio, which are compared with Planck + WMAP9 + BAO data, the power spectrum predicted by the new general DBI inflation theory satisfies the CMB Experiment constraints, i.e., is consistent with the current theories and experimental observations. Consequently, the theory of this paper conforms to current experiments and is supplying the current theories, and also a new way of explaining the inflation of the universe.

The very early universe

The universe at very early times, before the GUT era, is discussed. The entropy problem is described. The horizon and flatness problems are subsumed into the general problem of finding plausible models of the physics of the Planck era or the era immediately after it. An outline of inflationary cosmology is given, including quantitative treatment of a scalar inflaton field, treated in both a classical and quantum approach, in order to find the average dynamics and the spectrum of perturbations, respectively.

On the Trans-Planckian Censorship Conjecture and the generalized non-minimal coupling

We investigate the Trans-Planckian Censorship Conjecture (TCC) and the arising bounds on the inflationary cosmology caused by that conjecture. In that investigation, we analyze TCC bounds for both Jordan and Einstein frames in the presence of a generic non-minimal coupling (to gravity) term. That term allows us to use the functional freedom it brings to the inflationary Lagrangian as an effective Planck mass. In this sense, we argue one should consider the initial field value of the effective Planck mass for the TCC. We show that as a result, one can remove the TCC upper bounds without the need to produce a new process or go beyond the standard inflation mechanism, with the generalized non-minimal coupling, and for Higgs-like symmetry-breaking potentials.

Re-interpretation of the Two-World Background of Special Relativity as Four-World Background II

Coexisting four universes in separate four-dimensional spacetimes constitute four-world background for the special theory of relativity (SR) in each universe, as developed in previous papers. The fact that the four universes exhibit perfect symmetry of state and perfect symmetry of natural laws is shown in this paper. The many universes concept involved is entitled compartment universes. Compartment universes are coexisting symmetrical universes in different fourdimensional spacetimes of identical extents. Material particles and bodies are symmetrically distributed in spacetimes and the same natural laws take on identical forms in compartment universes. These features differentiate the compartment universes concept from the multiverse of inflationary cosmology and the parallel branes of M-theory. The compartment universes concept opens new vista for many-world interpretations of the natural laws, as demonstrated for the special theory of relativity already, and it is a potential platform for the uniform formulation of the natural laws. Investigation of the possible existence of larger number of compartment universes than four and many-world interpretations of gravitation and other natural laws in the compartment universes picture are recommended.

Scalaron–Higgs inflation reloaded: Higgs-dependent scalaron mass and primordial black hole dark matter

We propose an extension of the scalaron-Higgs model by a non-minimal coupling of the Standard Model Higgs boson to the quadratic Ricci scalar resulting in a Higgs-dependent scalaron mass. The model predicts a successful stage of effective single-field Starobinsky inflation. It features a multi-field amplification mechanism leading to a peak in the inflationary power spectrum at small wavelengths which enhances the production of primordial black holes. The extended scalaron-Higgs model unifies inflationary cosmology with elementary particle physics and explains the origin of cold dark matter in terms of primordial black holes without assuming any new particles.