相关论文: A dark energy view of inflation
A rigorous constraint analysis on cosmic inflation entails several probes which collectively survey an extensive range of energy scales. We complement the cosmic microwave background data with an updated compilation of the cosmic abundance…
Recent fits of cosmological parameters by the Wilkinson Microwave Anisotropy Probe (WMAP) measurement favor a primordial scalar spectrum with varying index. This result, if stands, could severely constrain inflation model buildings. Most…
Dark energy (DE) models with many free parameters are often considered excessive, as constraining all parameters poses a significant challenge. While such models offer greater flexibility to probe the DE sector in more detail. With the…
This pedagogical review is devoted to quintessential inflation, which refers to unification of inflation and dark energy using a single scalar field. We present a brief but concise description of the concepts needed to join the two ends,…
The effect of the length of inflation on the power spectra of scalar and tensor perturbations is estimated using the power-law inflation model with a scale factor of a(t) = t^q. Considering various pre-inflation models with…
We consider a model of inflation consisting a single fluid with a time-dependent equation of state. In this phenomenological picture, two periods of inflation are separated by an intermediate non-inflationary stage which can be either a…
We constrain the evolution of the dark energy density from Cosmic Microwave Background, Large Scale Structure and Supernovae Ia measurements. While Supernovae Ia are most sensitive to the equation of state $w_0$ of dark energy today, the…
To derive a power spectrum for energy density inhomogeneities in a closed universe, we study a spatially-closed inflation-modified hot big bang model whose evolutionary history is divided into three epochs: an early slowly-rolling scalar…
We consider higher-dimensional uniform inflation, in which the extra dimensions expand at the same rate as three-dimensional non-compact space during inflation. We compute the cosmological perturbation in $D+4$ dimensions and derive the…
Constraints to the parameters of inflation models are often derived assuming some plausible range for the number--e.g., $N_k=46$ to $N_k=60$--of $e$-folds of inflation that occurred between the time that our current observable Universe…
A model-independent method to study the possible evolution of dark energy is presented. Optimal estimates of the dark energy equation of state w are obtained from current supernovae data from Riess et al. (2004) following a principal…
Scalar field with non-minimal coupling to curvature scalar is studied in Robertson-Walker background. The infrared limit of two point function, and, in turn, of the energy-momentum tensor of scalar field have been considered in the power…
We perform a study of cosmic evolution with an equation of state parameter $\omega(t)=\omega_0+\omega_1(t\dot H/H)$ by selecting a phenomenological $\Lambda$ model of the form, $\dot\Lambda\sim H^3$. This simple proposition explains both…
The Dark Side of the Universe, which includes the cosmological inflation in the early Universe, the current dark energy and dark matter, can be theoretically described by supergravity, though it is non-trivial. We recall the arguments pro…
Three-forms can give rise to viable cosmological scenarios of inflation and dark energy with potentially observable signatures distinct from standard single scalar field models. In this study, the background dynamics and linear…
The discovery of scale acceleration evidenced from supernovae luminosities and spatial flatness of feature evolution in the cosmic microwave background presents a challenge to the understanding of the evolution of cosmological vacuum…
The parameter space for A-term inflation is explored with $W=\lambda_p \phi^p/(p M_P^{p-3})$. With p=6 and \lambda_p~1, the observed spectrum and spectral tilt can be obtained with soft mass of order 10^2 GeV but not with a much higher…
Models of dark energy are conveniently characterized by the equation-of-state parameter w=p/\rho, where \rho is the energy density and p is the pressure. Imposing the Dominant Energy Condition, which guarantees stability of the theory,…
We present N-body simulation calculations of the dependence of the power spectrum of non-linear cosmological mass density fluctuations on the equation of state of the dark energy, w=p/rho. At fixed linear theory power, increasing w leads to…
We consider an ultra-light scalar field with a mass comparable to (or lighter than) the Hubble parameter of the present universe, and calculate the time evolution of the energy-momentum tensor of the vacuum fluctuations generated during and…