Given the proliferation of bouncing models in recent years, we gather and critically assess
these proposals in a comprehensive review. The PLANCK data shows an unmistakably red …

Ekpyrotic and cyclic cosmologies provide theories of the very early and of the very late
universe. In these models, the big bang is described as a collision of branes—and thus the …

We present the final nine-year maps and basic results from the Wilkinson Microwave
Anisotropy Probe (WMAP) mission. The full nine-year analysis of the time-ordered data …

In this paper, we present a new scenario of the early universe that contains a pre-big bang
ekpyrotic phase. By combining this with a ghost condensate, the theory explicitly violates the …

We study the cosmology of a galileon scalar-tensor theory, obtained by covariantizing the
decoupling Lagrangian of the Dvali-Gabadadze-Poratti (DGP) model. Despite being local in …

We review some theoretical and phenomenological aspects of massive gravities in 4
dimensions. We start from the Fierz–Pauli theory with Lorentz-invariant mass terms and then …

We study a model for a nonsingular cosmic bounce in N= 1 supergravity, based on
supergravity versions of the ghost condensate and cubic Galileon scalar field theories. The …

Performing a fully non-perturbative analysis using the tools of numerical general relativity,
we demonstrate that a period of slow contraction is a “supersmoothing” cosmological phase …

We show that curvature perturbations acquire a scale invariant spectrum for any constant
equation of state, provided the fluid has a suitably time-dependent sound speed. In order for …

We study the propagation of super-horizon cosmological perturbations in a non-singular
bounce spacetime. The model we consider combines a ghost condensate with a Galileon …