相关论文: Generalized Galilean Genesis

We study the bispectrum of the primordial curvature perturbation on uniform-density hypersurfaces generated by a kind of the noncanonical warm inflation, wherein the inflation is provided by a noncanonical scalar inflaton field that is…

We review some theoretical and statistical aspects of the origin of the large-scale structure in the Universe, in view of the two most widely known and accepted scenarios: the inflaton and the curvaton scenarios. Among the theoretical…

Horndeski/Galileons may be considered as a proper generalization of General Relativity in high energy regime. Thus one may search for manifestation of Galileons interaction in collision experiments. In this paper we give arguments…

In the approach of the effective field theory of modified gravity, we derive the second-order action and the equation of motion for tensor perturbations on the flat isotropic cosmological background. This analysis accommodates a wide range…

We compute in detail how deviations from Einstein gravity at the inflation energy scale could appear as non-Gaussian features in the sky. To illustrate this we use multi-field $\alpha-$attractor models in the framework of supergravity to…

We investigate the generalized cubic covariant Galileon model, a kinetically driven dark energy model within the Horndeski class of theories. The model extends the cubic covariant Galileon by including power laws of the field derivatives in…

We consider scalar-tensor theories of gravity in an accelerating universe. The equations for the background evolution and the perturbations are given in full generality for any parametrization of the Lagrangian, and we stress that apparent…

The reconstruction procedure, which has proven quite useful to obtain viable models of the universe evolution, is here employed in order to construct inflation models. It has the advantages that it ensures full consistency with astronomical…

We propose a model of the Universe based on Minkowski flat space-time metric. In this model the space-time does not evolve. Instead the matter evolves such that all the mass parameters increase with time. We construct a model based on…

We extend the \delta N formalism so that it gives all of the stochastic properties of the primordial curvature perturbation \zeta if the initial field perturbations are gaussian. The calculation requires only the knowledge of some family of…

Within the framework of the scalar-tensor theory we consider a hill-climbing inflation, in which the effective Planck mass increases in time. We obtain the Einstein frame potential with infinitely long and flat plateau as we approach…

For very general scalar-field theories in which the equations of motion are at second-order, we evaluate the three-point correlation function of primordial scalar perturbations generated during inflation. We show that the shape of…

We derive a general expression for the power spectra of scalar and tensor fluctuations generated during inflation given an arbitrary choice of boundary condition for the mode function at a short distance. We assume that the boundary…

Based on the Effective Field Theory (EFT) of cosmological perturbations, we explicitly clarify the pathology in nonsingular cubic Galileon models and show how to cure it in EFT with new insights into this issue. With the least set of EFT…

We describe how to reconstruct generalized scalar-tensor gravity (GSTG) theory, which admits exact solutions for physical type of the potentials. Our consideration deals with cosmological inflationary models based on GSTG with non-minimal…

We consider the non-commutative inflation model of [3] in which it is the unconventional dispersion relation for regular radiation which drives the accelerated expansion of space. In this model, we study the evolution of linear cosmological…

We investigate the cosmological perturbations in generalized gravity, where the Ricci scalar and a scalar field are non-minimally coupled via an arbitrary function. In the Friedmann-Lemaitre-Robertson-Walker background, by studying the…

We present a general and unified formulation which can handle the classical evolution and quantum generation processes of the cosmological gravitational wave in a broad class of generalized gravity theories. Applications are made in several…

Based on the conventional metric tensor and driven by a nearly constant energy density, cosmic inflation, characterized by a remarkably accelerated expansion, was proposed as an early epoch in the Universe. The energy density is typically…

We study the linear perturbations of multi-field inflationary models governed by a Lagrangian which is a general function of the scalar fields and of a global kinetic term combining their spacetime gradients with an arbitrary field space…