funnel (2 M$_{˜}$ χ 1 0 ≃ M$_{A}$ $^{0}$,H0 ). The mSUGRA parameter space in Figs. (12), for tan β = 10 and 40 with the udd flat direction using λ = 1. In the figures, we show contours correspond to n$_{s}$ = 1 for the maximum value of δ$_{H}$ = 2 . 03 × 10 − 5 (at 2 σ level) and n$_{s}$ = 1 . 0 , 0 . 98 , 0 . 96 for δ$_{H}$ = 1 . 91 × 10 − $^{5}$. It is also interesting to note that the allowed region of m$_{φ}$ , as required by the inflation data for λ = 1 lies in the stau-neutralino coannihilation region which requires smaller values of the SUSY particle masses. See Fig. (9), where both co-annihilation and focus point regions have been illustrated for λ ∼ 1 − 0 . 02. The SUSY particles in this parameter space are, therefore, within the reach of the LHC very quickly. The detection of the region at the LHC has been considered in [737]. From the figures, one can also find that as tan β increases, the inflation data along with the dark matter, rare decay and Higgs mass constraint allow smaller ranges of m$_{1}$$_{/}$$_{2}$ . For example, the allowed ranges of gluino masses are 765 GeV-2.1 TeV and 900 GeV-1.7 TeV for tan β = 10 and 40 respectively. Now if λ is small, i.e. λ < ∼ 10 − $^{1}$, the allowed values of m$_{φ}$ would be large. In this case the dark matter allowed region requires the lightest neutralino to have larger Higgsino component in the mSUGRA model. If the reheat temperature of the universe is higher than the mass of the inflaton, then the plasma upon reheating will, in addition, have a thermal distribution of the inflaton quanta. If the inflaton is absolutely stable, due to some symmetry, then it can also serve as the cold dark matter. One such example, NH$_{u}$L as an observable sector inflaton is an interesting scenario, as it can explain successful inflation, exciting SM quarks and leptons, the observed neutrino masses via Dirac coupling and the right handed sneutrino, ˜ N , as a dark matter candidate [716]. It is well known that for particles with gauge interactions, the unitarity bound puts an absolute upper bound on the dark matter mass to be less than ∼ 100 TeV [341]. Once the temperature drops below the inflaton mass, its quanta undergo thermal freeze-out and yield the correct dark matter abundance. Furthermore, scatterings via the new U $^{(1)$_{B}$}$− L gauge interactions also bring the right handed sneutrino into thermal equilibrium. Note that part of the inflaton, i.e. its ˜ N component see Eq. (334), has never decayed; only the coherence 164 2. Can dark matter be the inflaton?