Related papers: On what scale should inflationary observables be c…
We have evaluated the observational constraints on the spectral index $n$, in the context of a $\Lambda$CDM model. For $n$ scale-independent, as predicted by most models of inflation, present data require $n\simeq 1.0 \pm 0.1$ at the…
By writing the running of the scalar spectral index completely in terms of the scalar index $n_s$ and the tensor-to-scalar ratio $r$ we are able to impose constraints to models of inflation which are independent of the parameters of the…
Cosmological inflation predicts that the scalar spectral index "runs" with scale. Constraints on the values of the spectral runnings, $\alpha_s\equiv \textrm{d} n_s/\textrm{d}\ln k$ and $\beta_s\equiv \textrm{d}\alpha_s/\textrm{d}\ln k$,…
The scalar spectral index n is an important parameter describing the nature of primordial density perturbations. Recent data, including that from the WMAP satellite, shows some evidence that the index runs (changes as a function of the…
The WMAP results on the scalar spectral index n and its running with scale, though preliminary, open a very interesting window to physics at very high energies. We address the problem of finding inflaton potentials well motivated by…
We consider the running of the spectral index as a probe of both inflation itself, and of the overall evolution of the very early universe. Surveying a collection of simple single field inflationary models, we confirm that the magnitude of…
Some of the consequences for inflationary cosmology of a scale dependence (running) in the tilt of the scalar perturbation spectrum are considered. In the limit where the running is itself approximately scale-invariant, a relationship is…
Density perturbations generated from inflation almost always have a spectral index n_s which runs (varies with the wavelength). We explore a running spectral index scenario in which the scalar spectral index runs from blue (n_s >1) on large…
We constrain slow-roll inflationary models using the recent WMAP data combined with data from the VSA, CBI, ACBAR and 2dF experiments. We find the slow-roll parameters to be $0 < \epsilon_1 < 0.032$ and $\epsilon_2 + 5.0 \epsilon_1 = 0.036…
We present the constraints on inflationary parameters in a flat $\Lambda$CDM universe obtained by WMAP three year data release, plus smaller scale CMB and two LSS data sets, 2dF and SDSS (treated separately). We use a Markov Chain Monte…
Determining the energy scale of inflation is crucial to understand the nature of inflation in the early Universe. We place observational constraints on the energy scale of the observable part of the inflaton potential by combining the…
Models of inflationary cosmology based on spontaneous symmetry breaking typically suffer from the shortcoming that the symmetry breaking scale is driven to nearly the Planck scale by observational constraints. In this paper we investigate…
Three-year data of WMAP implies not only a negative running of the spectral index with large absolute value, but also a large positive running of running of the spectral index with order of the magnitude $10^{-2}$. We calculate the running…
We consider the observational constraints on the running-mass inflationary model, and in particular on the scale-dependence of the spectral index, from the new Cosmic Microwave Background (CMB) anisotropy measurements performed by WMAP and…
The spectral index of scalar perturbations is an important observable that allows us to learn about inflationary physics. In particular, a detection of a significant deviation from a constant spectral index could enable us to rule out the…
In light of the most recent cosmological observations, we provide new updated constraints on the slow-roll inflation in different extended scenarios beyond the $\Lambda\rm{CDM}$ cosmological model. Along with the usual six parameters, we…
We evaluate the observational constraints on the spectral index $n$, in the context of the $\Lambda$CDM hypothesis which represents the simplest viable cosmology. We first take $n$ to be practically scale-independent. Ignoring reionization,…
We investigate the cosmic inflation within a class of the scalar-tensor model with the scalar-dependent non-minimal kinetic couplings. The inflationary dynamical potential will be applied. Using the slow-roll approximation, we compute…
Accurate estimation of cosmological parameters from microwave background anisotropies requires high-accuracy understanding of the cosmological model. Normally, a power-law spectrum of density perturbations is assumed, in which case the…
Many, if not most, inflationary models predict the power-law index of the spectrum of density perturbations is close to one, though not precisely equal to one, |n-1| \sim O(0.1), implying that the spectrum of density perturbations is…