Related papers: Vector Field and Inflation
Motivated by the recent works of Refs. \cite{R1, R2} where a model of inflation has been suggested with non-minimally coupled massive vector fields, we generalize their work to the study of the bouncing solution. So we consider a massive…
We revisit the resulting bispectrum of inflation with kinetic-coupled vector fields by organizing the dynamics in terms of $h$, which measures the vector kinetic contribution relative to that of the scalar field. We evaluate the bispectrum…
It has recently been shown that the presence of a spectator pseudoscalar field, coupled to photons through a Chern-Simons term, can amplify the primordial tensor spectrum without observationally disrupting the primordial scalar spectrum.…
The initial condition problem of inflation is examined from the perspective of both spacetime embedding and scalar field dynamics. The spacetime embedding problem is solved for arbitrary initial spatial curvature Omega, which generalizes…
We consider inflation in a universe with a positive cosmological constant and a nonminimally coupled scalar field, in which the field couples both quadratically and quartically to the Ricci scalar. When considered in the Einstein frame and…
Rapid-turn slow-roll inflationary trajectories have been shown to be an attractor in two-field models, provided the turn rate is near constant and larger than the slow-roll parameters. These trajectories can produce primordial spectra…
In this paper, we investigate models where a scalar field driving inflation is minimally coupled with gravity and it is subjected to a scalar potential. We present several examples of coupling between the field and gravity, and we furnish…
We consider models of inflation with U(1) gauge fields and charged scalar fields including symmetry breaking potential, chaotic inflation and hybrid inflation. We show that there exist attractor solutions where the anisotropies produced…
Cosmological implication of a generalized model of two scalar and two vector fields, in which both scalar fields are non-minimally coupled to each vector field, is studied in this paper. In particular, we will seek a set of new anisotropic…
We consider the robustness of small-field inflation in the presence of scalar field inhomogeneities. Previous numerical work has shown that if the scalar potential is flat only over a narrow interval, such as in commonly considered…
We present uniform rate inflation in a modified $f(T, \mathcal{T}) $ gravity. It is found that early inflation can be realized even with a scalar field field with a quadratic potential and a negative cosmological constant. We construct…
Inflation models can have an early phase of inflation where the evolution of the inflaton is driven by quantum fluctuations before entering the phase driven by the slope of the scalar field potential. For a Coleman-Weinberg potential this…
We study an inflation mechanism based on attractor properties in cosmological evolutions of a spatially flat Friedmann-Robertson-Walker spacetime based on the Einstein-scalar field theory. We find a new way to get the Hamilton-Jacobi…
The inflationary scenario, which states that the early universe underwent a brief but dramatic period of accelerated spatial expansion, has become the current paradigm of early universe cosmology. Although inflationary cosmology has its…
We make use of possible high energy correction to the Friedmann equation to implement the bounce and study the behavior of massive scalar field before and after bounce semianalytically and numerically. We find that the slow-roll inflation…
While cosmological inflation can erase primordial inhomogeneities, it is possible that inflation may not begin in a significantly inhomogeneous universe. This issue is particularly pressing in multifield scenarios, where even the…
The leading account of several salient observable features of our universe today is provided by the theory of cosmic inflation. But an important and thus far intractable question is whether inflation is generic, or whether it is finely…
We investigate the range of inflationary universe models driven by scalar fields possessing a general interaction potential of the form $V(\phi) = V_0 \phi^n \exp(-\lambda \phi^m)$. Power-law, de Sitter and intermediate inflationary…
The possibility of the resilience of the beginning of inflation under unfavorable conditions is examined by considering the initial state of the inflaton field to be in the form of a relativistic gas with some of its properties in close…
We examine inflationary universe models driven by scalar fields with logarithmic potentials of the form $V(\phi) = V_0 \phi^p(\ln \phi)^q$. Combining the slow-roll approximation with asymptotic techniques, we identify regions of the…