arXiv subjects

Chia-Min Lin

Publications and source records attributed to Chia-Min Lin.

58 records · Page 4Linked to original sources

arXiv2009

Super Hilltop Inflation

In this paper, we consider logarithmic radiative corrections and higher order terms to the supersymmetric hilltop F- and D-term hybrid inflation models. Conventional F- and D-term hybrid inflation only predicts $n_s \gae 0.98$. We show that via a positive quadratic and a negative quartic correction the spectral index can be reduced to $n_s=0.96$ suggested from latest WMAP result and also cosmic string problem appeared in SUSY hybrid inflation can be solved with mild tuning of the parameters if $κ\lae 0.01$ for F-term inflation and $g \lae 0.05$ for D-term inflation.

hep-ph↗

arXiv2008

Supergravity and Two-Field Inflation Effects in Right-Handed Sneutrino-Modified D-term Inflation

We extend previous work on the minimal D-term inflation model modified by Right-Handed (RH) sneutrino fields to include additional inflaton-sector SUGRA corrections and two-field inflation effects. We show that SUGRA corrections simultaneously allow n_{s} to be within 3-year WMAP limits and the cosmic string contribution to the CMB power spectrum to be less than 5%. For gauge coupling g < 1, the CMB contribution from cosmic strings is predicted to be at least 1% while the spectral index is predicted to be less than 0.968 for a CMB string contribution less than 5%. Treating the inflaton-RH sneutrino system as a two-field inflation model, we show that the time-dependence of the RH sneutrino field strongly modifies the single-field results for values of RH sneutrino mass m_Φ > 0.1 H. The running spectral index is α= -0.0002 when m_Φ < 0.1 H but increases to positive values as m_Φ/H increases, with α> 0.008 for m_Φ > 1.0 H.

hep-ph↗

arXiv2007

More hilltop inflation models

Using analytic expressions, we explore the parameter space for hilltop inflation models with a potential of the form $V_0\pm m^2ϕ^2 -aϕ^p$. With the positive sign and p>2 this converts the original hybrid inflation model into a hilltop model, allowing the spectral index to agree with the observed value n=0.95. In some cases the observed value is theoretically favored, while in others there is only the generic prediction $|n-1|\lsim 1$.

hep-ph↗

arXiv2006

Supergravity Modification of D-term Hybrid Inflation: Solving the Cosmic String and Spectral Index Problems via a Right-Handed Sneutrino

Supergravity corrections due to the energy density of a right-handed sneutrino can generate a negative mass squared for the inflaton, flattening the inflaton potential and reducing the spectral index and inflaton energy density. For the case of D-term hybrid inflation, we show that the spectral index can be lowered from the conventional value n = 0.98 to a value within the range allowed by the latest WMAP analysis, n = 0.951^{+0.015}_{-0.019}. The modified energy density is consistent with non-observation of cosmic strings in the CMB if n < 0.946. The WMAP lower bound on the spectral index implies that the D-term cosmic string contribution may be very close present CMB limits, contributing at least 5% to the CMB multipoles.

hep-ph↗