AbstractWe propose a minimal model that can explain the electroweak scale, neutrino masses, Dark Matter (DM), and successful inflation all at once based on the multicritical-point principle (MPP). The model has two singlet scalar fields that realize an analogue of the Coleman–Weinberg mechanism, in addition to the Standard Model with heavy Majorana right-handed neutrinos. By assuming a $$Z_2 $$
Z
2
symmetry, one of the scalars becomes a DM candidate whose property is almost the same as the minimal Higgs-portal scalar DM. In this model, the MPP can naturally realize a saddle point in the Higgs potential at high energy scales. By the renormalization-group analysis, we study the critical Higgs inflation with non-minimal coupling $$\xi |H|^2 R$$
ξ
|
H
|
2
R
that utilizes the saddle point of the Higgs potential. We find that it is possible to realize successful inflation even for $$\xi =25$$
ξ
=
25
and that the heaviest right-handed neutrino is predicted to have a mass around $$10^{14}$$
10
14
$$\mathrm{GeV}$$
GeV
to meet the current cosmological observations. Such a small value of $$\xi $$
ξ
can be realized by the Higgs-portal coupling $$\lambda _{SH}\simeq 0.32$$
λ
SH
≃
0.32
and the vacuum expectation value of the additional neutral scalar $$\langle \phi \rangle \simeq 2.7$$
⟨
ϕ
⟩
≃
2.7
TeV, which correspond to the dark matter mass 2.0 TeV, its spin-independent cross section $$1.8\times 10^{-9}$$
1.8
×
10
-
9
pb, and the mass of additional neutral scalar 190 GeV.
A theory of giant vortices