TY - JOUR

T1 - Minimal R + R2 supergravity models of inflation coupled to matter

AU - Ferrara, Sergio

AU - Porrati, Massimo

N1 - Funding Information:
We are grateful to R. Kallosh and A. Linde for stimulating collaborations on related previous investigations and to A. Kehagias for useful discussions. S.F. is supported by ERC Advanced Investigator Grant No. 226455 Supersymmetry, Quantum Gravity and Gauge Fields (Superfields). M.P. is supported in part by NSF grant PHY-1316452 . M.P. would like to thank CERN for its kind hospitality and the ERC Advanced Investigator Grant No. 226455 for support while at CERN.

PY - 2014/10/7

Y1 - 2014/10/7

N2 - The supersymmetric extension of "Starobinsky" R + αR2 models of inflation is particularly simple in the "new minimal" formalism of supergravity, where the inflaton has no scalar superpartners. This paper is devoted to matter couplings in such supergravity models. We show how in the new minimal formalism matter coupling presents certain features absent in other formalisms. In particular, for the large class of matter couplings considered in this paper, matter must possess an R-symmetry, which is gauged by the vector field which becomes dynamical in the "new minimal" completion of the R + αR2 theory. Thus, in the dual formulation of the theory, where the gauge vector is part of a massive vector multiplet, the inflaton is the superpartner of the massive vector of a nonlinearly realized R-symmetry. The F-term potential of this theory is of no-scale type, while the inflaton potential is given by the D-term of the gauged R-symmetry. The absolute minimum of the potential is always exactly supersymmetric, so in this class of models if realistic vacua exist, they must be always metastable. We also briefly comment on possible generalizations of the examples discussed here and we exhibit some features of higher-curvature supergravity coupled to matter in the "old minimal" formalism.

AB - The supersymmetric extension of "Starobinsky" R + αR2 models of inflation is particularly simple in the "new minimal" formalism of supergravity, where the inflaton has no scalar superpartners. This paper is devoted to matter couplings in such supergravity models. We show how in the new minimal formalism matter coupling presents certain features absent in other formalisms. In particular, for the large class of matter couplings considered in this paper, matter must possess an R-symmetry, which is gauged by the vector field which becomes dynamical in the "new minimal" completion of the R + αR2 theory. Thus, in the dual formulation of the theory, where the gauge vector is part of a massive vector multiplet, the inflaton is the superpartner of the massive vector of a nonlinearly realized R-symmetry. The F-term potential of this theory is of no-scale type, while the inflaton potential is given by the D-term of the gauged R-symmetry. The absolute minimum of the potential is always exactly supersymmetric, so in this class of models if realistic vacua exist, they must be always metastable. We also briefly comment on possible generalizations of the examples discussed here and we exhibit some features of higher-curvature supergravity coupled to matter in the "old minimal" formalism.

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U2 - 10.1016/j.physletb.2014.08.050

DO - 10.1016/j.physletb.2014.08.050

M3 - Article

AN - SCOPUS:84906686739

SN - 0370-2693

VL - 737

SP - 135

EP - 138

JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

ER -