arXiv subjects

Ping Kwan Man Ellgan

Publications and source records attributed to Ping Kwan Man Ellgan.

3 recordsLinked to original sources

arXiv2020

Modification of T/E models and their multi-field versions

We propose a modification on the super-potential of (arXiv: 1901.09046) which discusses the simplest construction of inflationary $α$ attractor models (also called T/E models) in supergravity without the sinflaton. This can make all the components of the first derivative vanish at the minimum point after the specific choice for the modified part. We also extend T/E models into the multi-field versions, motivated by considering the effect of multi orthogonal nilpotent super-fields, whose sgoldstino, sinflatons and inflatinos are very heavy such that we can take the orthogonal nilpotent constraints to obtain physical limits. Finally, we study the inflation dynamics in the double field cases of both T and E models and show their turning rates and the square mass of the entropic perturbation, which can be used for further observational verification.

hep-ph↗

arXiv2019

Phenomenology of SUGRA Extensions of the Starobisnky Model

We analyze BI model in a complete form and compare the predictions with that of Starobinsky model. Under the parameter constraints in Planck 2018, we find that the dynamics of the whole inflation process described by BI and Starobinsky models are nearly the same, even though there are some differences in the regions out of inflation. We also find the scales of parameters in BI model and initial inflaton values required to implement inflation. The changes of $\left( {n}_{s}, r \right)$ fingerprints of BI model and that of evolutions of inflaton field due to the variations of relevant parameters are also investigated.

gr-qc↗

arXiv2019

Slow-roll Analysis of Double Field Axion Inflation

We adopt the double field natural inflation model motivated by the non-perturbative effects of supergravity and superstring theory to do the slow roll analysis. We show that when the parameters are suitably chosen, there exist ranges of initial values of fields that can satisfy the constraints of Planck observations. This implies less fine tuning of field values can be allowed with tolerance of $4 {M}_{\text{pl}}$ for $ϕ_{1}$ and $5 {M}_{\text{pl}}$ for $ϕ_{2}$ respectively, which become more physical for field fluctuation in quantum era. We also show that the spectral index ${n}_{\mathcal{RR}}$, the fraction of entropic power spectrum and the fraction of power spectra (so-called $β_{\text{iso}}$) and $\cosΔ$ can satisfy the constraints of Planck observation. This implies that double field natural inflation is a valid model to describe cosmological inflation.

gr-qc↗