Induced-gravity GUT-scale Higgs inflation in supergravity

Abstract

Models of induced-gravity inflation are formulated within Supergravity employing as inflaton the Higgs field which leads to a spontaneous breaking of a U (1) B−L symmetry at M GUT = 2 • 10 16 GeV. We use a renormalizable superpotential, fixed by a U (1) R symmetry, and Kähler potentials which exhibit a quadratic non-minimal coupling to gravity with or without an independent kinetic mixing in the inflaton sector. In both cases we find inflationary solutions of Starobinsky type whereas in the latter case, others (more marginal) which resemble those of linear inflation arise too. In all cases the inflaton mass is predicted to be of the order of 10 13 GeV. Extending the superpotential of the model with suitable terms, we show how the MSSM μ parameter can be generated. Also, non-thermal leptogenesis can be successfully realized, provided that the gravitino is heavier than about 10 TeV.

Unitarizing non-minimal inflation via a linear contribution to the frame function

“…V -, the classical approximation, used in our analysis is perfectly valid. Finally, it is worth emphasize that V CI is of Starobinsky-type although φ = 0 in sharp contrast to the models of induced-gravity inflation [16,18,19] where φ ≫ 0.…”

“…In the case of highscale nMI this problem can be also eluded invoking a large inflaton vacuum expectation value (v.e.v) φ as in Refs. [16][17][18][19]. Unitarity-conserving nMI can be also achieved by considering a scalar field, which exhibits a linear contribution to its non-minimal coupling to gravity, in addition to the Standard Model (SM) Higgs field which is coupled quadratically to gravity [20,21].…”

Unitarity-safe models of non-minimal inflation in supergravity

“…Several ways have been proposed to surpass the inconsistency above. E.g., incorporating new degrees of freedom at attr UV [21], or assuming additional interactions [22], or invoking a large inflaton vacuum expectation value (v.e.v) φ [23][24][25][26][27], or introducing a sizable kinetic mixing in the inflaton sector which dominates overf R [28][29][30][31][32][33][34].…”

“…[33,34] whereas the gauge-symmetry-breaking scale is constrained to values well below the MSSM unification scale contrary to what happens in Refs. [27,33,34].…”

Inflation in gauge theory of gravity with local scaling symmetry and quantum induced symmetry breaking

“…Induced gravity can be generally referred as theories where the Planck scale is generated by other fields [3,4]. In the literature, global scaling symmetry has been used in building inflation models (see [5][6][7][8][9][10][11][12][13][14][15] for examples), aiming to introduce no dimensional parameters or explain the heirarchies between different energy scales. As we shall see, whether the scaling symmetry is global or local actually has some important differences.…”