Related papers: Open universes from bubbles: an introduction and u…
I report on recent developments in the theory of cosmic background radiation perturbations. I describe ways of modeling alternatives to the canonical Gaussian theories within the standard framework of cosmological perturbation theory. Some…
The idea that the universe might be open is an old one, and the possibility of having an open universe arise form inflation is not new either. However, a concrete realization of a consistent single-bubble open inflation model is known only…
Open Inflation has recently been suggested as a possible way out of the age crisis caused by observations of a large rate of expansion of the universe, in conflict with the existence of very old globular clusters. It proposes that our local…
I review in these lectures our present understanding of the origin and evolution of the universe, making emphasis on the most recent observations of the acceleration of the universe, the precise measurements of the microwave background…
An introductory account is given of the modern understanding of the physics of the early Universe. Particular emphasis is placed on the paradigm of cosmological inflation, which postulates a period of accelerated expansion during the…
This contribution gives a brief overview of the theoretical ideas underlying our current understanding of the early Universe. Confronting the predictions of the early Universe models with cosmological observations, in particular of the…
A simple model of a universe is presented composed of black holes and black branes. It uses the most simplest approximations and models of General Relativity and Quantum Dynamics to offer an idea of an unification and gives a possible…
In this talk, I review some recent work on cosmic microwave background (CMB) anisotropies in an open universe. I emphasize that the observed CMB anisotropies are still consistent with a low value of $\Omega$, and I address the question of…
Most of the cosmological information extracted from the CMB has been obtained through the power spectrum, however there is much more to be learnt from the statistical distribution of the temperature random field. We review some recent…
We evaluate the possibility of observable effects arising from collisions between vacuum bubbles in a universe undergoing false-vacuum eternal inflation. Contrary to conventional wisdom, we find that under certain assumptions most positions…
In this talk, I review a number of particle-physics models that lead to the creation of magnetic fields in the early universe and address the complex problem of evolving such primordial magnetic fields into the fields observed today.…
I briefly discuss recent results of numerical simulations addressing the generation of a cosmological gravitational wave background produced by turbulence sources in the early universe. Contribution to the 2021 Gravitation session of the…
This is a very informal report that gives further details on the evidence for a bubble universe based on an anomaly in the angular distribution of quasar magnitudes that was presented in a short paper in arXiv:1202.4433. This report…
An introduction to modern theories for the origin of structure in the Universe is given. After a brief review of the growth of cosmological perturbations in an expanding Universe and a summary of some important observational results, the…
The interior of a vacuum bubble in de Sitter space may give an open universe with sufficient homogeneity to agree with observations. Here, previous work by Bucher, Goldhaber and Turok is extended to describe a thin bubble wall with nonzero…
Our universe may have formed via bubble nucleation in an eternally-inflating background. Furthermore, the background may have a compact dimension--the modulus of which tunnels out of a metastable minimum during bubble nucleation--which…
The recent high-quality measurements of the Cosmic Microwave Background anisotropies have presented cosmologists with the possibility of studying the large scale properties of our universe with unprecedented precision. Here I review the…
In a model recently proposed by Albrecht and Skordis it was suggested that the observed accelerated expansion of the universe could be caused by a scalar field which is trapped in a local minimum of an exponential potential modified by a…
If our universe has appeared in a result of Big Bang or something like this, whether we have reasons to deny an existence of other universes appearing by the same or similar way? An objection that there is no anything like it, is doubtful,…
We discuss the essential features of baby-universe production, starting from a description of black holes and wormholes, in terms of the causal structure of spacetime, and following a qualitative review of the connection between vacuum…