Related papers: Inflation and the dwarf galaxy problem
Recently multi-field inflation models that can produce large scalar fluctuations on small scales have drawn a lot of attention, primarily because they could lead to primordial black hole production and generation of large second-order…
Inflation during rapid oscillation of a scalar field in non-minimal derivative coupling model is discussed. Cosmological perturbations originated in this stage are studied and consistency of the results with observational constraints coming…
We study the cosmological inflation from the viewpoint of the moduli stabilization. We study the scenario that the superpotential has a large value during the inflation era enough to stabilize moduli, but it is small in the true vacuum.…
Recent high-resolution simulations of the formation of dark-matter halos have shown that the distribution of subhalos is scale-free, in the sense that if scaled by the velocity dispersion of the parent halo, the velocity distribution…
The standard big bang cosmological model and the history of the early universe according to the grand unified theories of strong, weak and electromagnetic interactions are summarized. The shortcomings of big bang are discussed together with…
We propose a topological inflation model in the framework of supergravity with $R$ invariance. This topological inflation model is not only free from the initial value problem of the inflaton field but also gives low reheating temperature…
Inflation models make specific predictions for a tensor-scalar-scalar three-point correlation, or bispectrum, between one gravitational-wave (tensor) mode and two density-perturbation (scalar) modes. This tensor-scalar-scalar correlation…
A wide variety of vacua, and their cosmological realization, may provide an explanation for the apparently anthropic choices of some parameters of particle physics and cosmology. If the probability on various parameters is weighted by…
Recent observations suggest the existence of a white dwarf population in the Galactic halo, while others suggest that deuterium has been astrated in systems at high redshift and low metallicity. We propose that these observations could be…
We explore the observational implications of models of intermediate inflation driven by modified dispersion relations, specifically those representing the phenomenon of dimensional reduction in the ultraviolet limit. These models are…
We generalize the cosmological duality between inflation and cyclic contraction under the interchange $a \leftrightarrow H$ to the case of non-canonical scalar field theories with varying speed of sound. The single duality in the canonical…
Hybrid inflation is a two field model where inflation ends due to an instability. In the neighborhood of the instability point, the potential is very flat and the quantum fluctuations dominate over the classical motion of the inflaton and…
According to the now strongly supported concordance $\Lambda$CDM model, galaxies may be grossly described as a luminous component embedded in a dark matter halo. The density profile of these mass dominating haloes may be determined by N -…
Observations of the cosmic microwave sky are revealing the primordial non-uniformities from which all structure in the Universe grew. The only known physical mechanism for generating the inhomogeneities we see involves the amplification of…
I demonstrate that instability in a system of homogeneous scalar fields leads to the growth of super-Hubble metric perturbations. This generalizes the result that parametric resonance can lead to the growth of cosmological perturbations.…
Numerical relativity simulations provide a means by which to study the evolution and end point of strong over-densities in cosmological spacetimes. Specific applications include studies of primordial black hole formation and the robustness…
Galaxy surveys have shown that luminous galaxies are mainly distributed in large filaments and galaxy clusters. The remaining large volumes are virtually devoid of luminous galaxies. This is in concordance with the formation of the…
I show that cosmological perturbation spectra produced from quantum fluctuations in massless or self-interacting scalar fields during an inflationary era remain invariant under a two parameter family of transformations of the homogeneous…
We interpret cosmological evolution holographically as a renormalisation group flow in a dual Euclidean field theory, as suggested by the conjectured dS/CFT correspondence. Inflation is described by perturbing around the infra-red fixed…
Quantum gravitational back-reaction offers the potential of simultaneously resolving the problem of the cosmological constant and providing a natural model of inflation in which scalars play no special role. In this model inflation begins…