Particle physics models of inflation and curvaton scenarios

Abstract

We review the particle theory origin of inflation and curvaton mechanisms for generating large scale structures and the observed temperature anisotropy in the cosmic microwave background (CMB) radiation. Since inflaton or curvaton energy density creates all matter, it is important to understand the process of reheating and preheating into the relevant degrees of freedom required for the success of Big Bang Nucleosynthesis. We discuss two distinct classes of models, one where inflaton and curvaton belong to the hidden sector, which are coupled to the Standard Model gauge sector very weakly. There is another class of models of inflaton and curvaton, which are embedded within Minimal Supersymmetric Standard Model (MSSM) gauge group and beyond, and whose origins lie within gauge invariant combinations of supersymmetric quarks and leptons. Their masses and couplings are all well motivated from low energy physics, therefore such models provide us with a unique opportunity that they can be verified/falsified by the CMB data and also by the future collider and non-collider based experiments. We then briefly discuss stringy origin of inflation, alternative cosmological scenarios, and bouncing universes.

Figures (20)

• Figure 1: Two-dimensional likelihood for the spectral index, the running and the ratio tensor/scalar, from the WMAP data only (blue) and the WMAP data combined with the BAO and supernovae data sets (red) at $1\sigma$ and $2\sigma$. Figures are taken from Komatsu:2008hk.
• Figure 2: Two-dimensional likelihood between the fraction of cosmic strings $f_{10}$ and the normalization and tilt of the power spectrum. Figures are taken from Bevis:2007gh.
• Figure 3: Normalized scalar potential of SM inflation in the Einstein frame, in the classical approximation (green), or taking into account quantum corrections for $m_h=126.5$ GeV and $m_h=128$ GeV, in blue and red respectively. Figure is taken from DeSimone:2008ei.
• Figure 4: Spectral index for $F$-term hybrid inflation with minimal kinetic terms (top green curve) and non-renormalizable corrections to the Kähler. Figure is taken from urRehman:2006hu.
• Figure 5: Initial condition space for $F$-term hybrid inflation in minimal SUGRA, when restricting to the sub-Planckian ($M_{\rm pl}=M_{\rm P}$) initial VEVs and vanishing velocities. The color code represents the number of e-foldings generated for each initial VEVs. This confirms that hybrid inflation is successful when the onset of inflation occurs close to the inflationary valley (the white narrow band along the y-axis), but shows a subdominant space for other trajectories where inflation is also successful for the sub-Planckian VEVs Clesse:2009ur.