Related papers: $\phi^2$ or Not $\phi^2$: Testing the Simplest Inf…
A simple model of quintessential inflation with the modified exponential potential $e^{-\alpha \phi} [A+(\phi-\phi_0)^2]$ is analyzed in the braneworld context. Considering reheating via instant preheating, we conclude that the model…
We present a simple formula that allows to calculate the value of the inflaton field, denoted by $\phi$, at the scale with wavenumber mode $k$. In the extreme case of instantaneous reheating $\phi_k$ is calculated exactly and all…
Last year we argued that if slow-roll inflation followed the decay of a false vacuum in a large landscape, the steepening of the scalar potential between the inflationary plateau and the barrier generically leads to a potentially observable…
We revisit the quadratic inflationary potential by introducing a minimal higher-order correction obtained through a simple field redefinition, leading to the potential V(chi) = (1/2) m^2 * (chi - (gamma/14) * chi^7)^2. While the uncorrected…
The tensor fraction $r\simeq 0.16$ found by BICEP2 corresponds to a Hubble parameter $H\simeq 1.0\times 10^{14}\GeV$ during inflation. This has two implications for the (single-field) slow-roll inflation hypothesis. First, the inflaton…
We find the best-fit cosmological parameters for a scenario of inflation with only the sufficient amount of accelerated expansion for the $\lambda\phi^4$ potential. While for the simplest scenario of chaotic inflation all observable…
The simplest $\alpha$-attractor $T$ model is given by the potential $V=V_0\tanh^2(\lambda\phi/M_{pl})$. However its generalization to the class of models of the type $V = V_0 \tanh^p (\lambda \phi/M_{pl})$ is difficult to interpret as a…
In this talk we discuss a model of inflation based on a simple variant of the NMSSM, called $\phi$NMSSM \cite{phiNMSSM}, where the additional singlet $\phi$ plays the role of the inflaton in hybrid (or inverted hybrid) type models. As in…
In a variety of inflation models the motion of the inflaton may trigger the production of some non-inflaton particles during inflation, for example via parametric resonance or a phase transition. Particle production during inflation leads…
We revisit the renormalizable polynomial inflection point model of inflation, focusing on the small field scenario which can be treated fully analytically. In particular, the running of the spectral index is predicted to be $\alpha = -1.43…
By incorporating both the tensor-to-scalar ratio and the measured value of the spectral index, we set a bound on solo small field inflation of $\Delta \phi / m_{Pl} \geq 1.00 \sqrt{r/0.1}$. Unlike previous bounds which require monotonic…
The recent results of the BICEP and Keck collaborations have put stringent bounds on many inflationary models, including some well-motivated ones. This is certainly the case when gravity remains described by Einstein's theory up to the…
We analyse the effect of the non-minimal coupling of the form $\xi\phi^2R/2$ on the single field inflation. If the non-minimal coupling is large, it relaxes the constraint on the field self coupling, making it possible to use the Standard…
Recent released WMAP data show a low value of quadrupole in the CMB temperature fluctuations, which confirms the early observations by COBE. In this paper we consider a model of two inflatons with different masses, $V(\phi_1,\phi_2)={1\over…
In the context of the Higgs model involving gauge and Yukawa interactions with the spontaneous gauge symmetry breaking, we consider $\lambda \phi^4$ inflation with non-minimal gravitational coupling, where the Higgs field is identified as…
Recently, Cormier and Holman pointed out that fluctuations of an inflaton field $\phi$ are significantly enhanced in the model of {\it spinodal inflation} with a potential $V(\phi)$ for which the second derivative $V^{(2)}(\phi)$ changes…
We investigated inflation in the Higgs-$R^2$ model and assumed the trajectory to follow a single-field approximation called minimal two-field mode. Using this approximation, we tried to constrain the Higgs' non-minimal coupling $\xi$.…
We propose a model of inflation based on a simple variant of the NMSSM, called $\phi$NMSSM, where the additional singlet $\phi$ plays the role of the inflaton in hybrid (or inverted hybrid) type models. As in the original NMSSM, the…
We construct two simple effective field theory versions of {\it Hybrid Natural Inflation (HNI)} that illustrate the range of its phenomenological implications. The resulting inflationary sector potential, $V=\Delta^4(1+a\cos(\phi/f))$,…
A new inflationary scenario whose exponential potential $V(\Phi)$ has a quadratic dependence on the field $\Phi$ in addition to the standard linear term is confronted with the tree-year observations of the Wilkinson-Microwave Anisotropy…