相关论文: Higgsed Chromo-Natural Inflation
Supersymmetric theories often include the non-compact directions in the field space along which the tree level potential grows only up to a certain limited value (determined by the mass scale of the theory) and then stays constant for the…
We investigate the properties of gravitational waves generated by heating induced phase transitions in warm inflation. In this scenario, the heating phase of inflation followed by subsequent cosmological cooling can trigger two associated…
We discuss a cosmological scenario with a stochastic background of gravitational waves sourced by the tensor perturbation due to a hybrid inflationary model with cubic potential. The tensor-to-scalar ratio for the present hybrid…
Primordial null energy condition (NEC) violation would imprint a blue-tilted spectrum on gravitational wave background (GWB). However, its implications on the GWB might be far richer than expected. We present a scenario, in which after a…
During inflation long wavelength gravitational waves are produced, which form stochastic background in the present universe with very wide range of frequencies. Higher frequency gravitational waves never experience super-Hubble-radius…
Comparison of theobservedanisotropy with that predicted iadiabaticDM models suggest that much of thserved signal may be due to long wavelenh gravitational waves. In inflationary models this requires the generation of tensor fluctuations to…
The behaviour of quantum metric perturbations produced during inflation is considered at the stage after the second Hubble radius crossing. It is shown that the classical correlation between amplitude and momentum of a perturbation mode,…
Inflation produces a primordial spectrum of gravity waves in addition to the density perturbations which seed structure formation. We compute the signature of these gravity waves in the large scale shear field. In particular, the shear can…
Motivated by BICEP2 results on the CMB polarization B-mode which imply primordial gravitational waves are produced when the Universe has the expansion rate of about $H \approx 10^{14}$ GeV, and by deviations from a smooth power-law…
The prospects for direct measurements of inflationary gravitational waves by next generation interferometric detectors inferred from the possible detection of B-mode polarization of the cosmic microwave background are studied. We compute…
We consider the classical fluctuations of the gravitational constant generated by bubbles in the inflationary universe. For extended inflation, we demonstrate numerically how and how large fluctuations are produced during bubble expansion.…
Recently, pulsar timing array (PTA) collaborations, including NANOGrav, have reported evidence of a stochastic gravitational wave background within the nHz frequency range.\ It can be interpreted by gravitational waves from preheating era.…
The large-scale magnetic fields arising from the quantum mechanical fluctuations of the hypercharge are investigated when the evolution of the gauge coupling is combined with a sufficiently long inflationary stage. In this framework the…
The primordial curvature perturbation \zeta may be generated by some curvaton field \sigma, which is negligible during inflation and has more or less negligible interactions until it decays. In the current scenario, the curvaton starts to…
We study cosmological gravitational particle production (CGPP) in Higgs inflation, wherein the inflaton is a scalar field with quartic self-coupling $\lambda$ and a nonminimal coupling to gravity $\xi$, and which may, but need not be, the…
The reheating of the universe after hybrid inflation proceeds through the nucleation and subsequent collision of large concentrations of energy density in the form of bubble-like structures moving at relativistic speeds. This generates a…
Recently it was shown that an inflationary background can be realized by any $p$-form field non-minimally coupled to gravity. In this paper, we study gravitational waves generated during p-form inflation. Even though the background…
We study higher curvature corrections to the scalar spectral index, the tensor spectral index, the tensor-to-scalar ratio, and the polarization of gravitational waves. We find that the higher curvature corrections can not be negligible in…
Holographic considerations may provide a glimpse of quantum gravity beyond what is currently accessible by other means. Here we apply holography to inflationary cosmology. We argue that the appropriate holographic bound on the total entropy…
We study the production, spectrum and detectability of gravitational waves in models of the early Universe where first order phase transitions occur during inflation. We consider all relevant sources. The self-consistency of the scenario…