Related papers: A comment about the cosmology on a bubble wall
Constructing an explicit compactification yielding a metastable de Sitter (dS) vacuum in a UV consistent string theory is an incredibly difficult open problem. Motivated by this issue, as well as the conjecture that all non-supersymmetric…
We discuss a holographic description of vacuum bubbles, with possible implications for a consistent description of the multiverse. In particular, we elaborate on the recent observation by Maldacena, that the interior of AdS bubbles can be…
How the spacetime evolved non-perturbatively in a landscape with multiple anti-de Sitter (AdS) vacua, which is theoretically well-motivated, has always been a matter of concern. As a step towards this issue, we perform (3+1)D numerical…
We initiate a study of cosmology within the framework of Maldacena's AdS/CFT correspondence. We present a comprehensive analysis of the classical motion of a charged domain wall that separates an external Reissner-Nordstrom region of…
We classify the cosmological behaviors of the domain wall under junctions between two spacetimes in terms of various parameters: cosmological constants of bulk spacetime, a tension of a domain wall, and mass parameters of the black…
Much work has been devoted to the phenomenology and cosmology of the so-called braneworld universe, where our (3+1)-dimensional universe lies on a brane surrounded by a (4+1)-dimensional bulk spacetime that is essentially empty except for a…
The primordial Universe might be highly inhomogeneous. We perform the 3+1D Numerical Relativity simulation for the evolution of scalar field in an initial inhomogeneous expanding Universe, and investigate how it populates the landscape with…
We consider an alternative scenario of inflation which can account for a spatially open universe. It is similar to the old inflation in which the bubble nucleation occurs in the sea of false vacuum, but differs from it in that the second…
We propose an alternative inflationary universe scenario in the context of Randall-Sundrum braneworld cosmology. In this new scenario the existence of extra-dimension(s) plays an essential role. First, the brane universe is initially in the…
The creation of the inflationary brane universe in 5d bulk Einstein and Einstein-Gauss-Bonnet gravity is considered. We demonstrate that emerging universe is ambigious due to arbitrary function dependence of the junction conditions (or…
We investigate the holographic quantum entanglement of a visible universe in an inflationary cosmology. To do so, we consider an AdS space with a dS boundary which represents an expanding space in time. In an inflationary cosmology, there…
A Gauss-Bonnet term naturally appears in the action for gravity when one considers the existence of space time with dimensions more than 1+3. A variety of inflationary models can be obtained within such a framework, once the scale factor…
We consider the cosmology of a pair of domain walls bounding a five-dimensional bulk space-time with negative cosmological constant, in which the distance between the branes is not fixed in time. Although there are strong arguments to…
We calculate the power spectrum of adiabatic density perturbations in an open inflationary model in which inflation occurs in two stages. First an epoch of old inflation creates a large, smooth universe, solving the horizon and homogeneity…
We propose a Euclidean preparation of an asymptotically AdS$_2$ spacetime that contains an inflating dS$_2$ bubble. The setup can be embedded in a four dimensional theory with a Minkowski vacuum and a false vacuum. AdS$_2$ times 2-sphere…
The estimation of the cosmological constant in inflationary Brane New World models is done. It is shown that basically it is quite large, of the same order as in anomaly-driven inflation. However, for some fine-tuning of bulk gravitational…
Bucher [Bucher2001] has recently proposed an interesting brane-world cosmological scenario where the ``Big Bang'' hypersurface is the locus of collision of two vacuum bubbles which nucleate in a five dimensional flat space. This gives rise…
Perhaps the deepest mystery of our accelerating Universe in expansion is the existence of a tiny and rigid cosmological constant, $\Lambda$. Its size is many orders of magnitude below the expected one in the standard model of particle…
We show that the non-supersymmetric AdS instability conjecture can point to how quantum gravity removes the initial Big Bang singularity, leading to a potential resolution for the past-incomplete inflationary universe. From the constraints…
We explore an effective 4D cosmological model for the universe where the variable cosmological constant governs its evolution and the pressure remains negative along all the expansion. This model is introduced from a 5D vacuum state where…