Upper Bound on the Tensor-to-Scalar Ratio in GUT-Scale Supersymmetric Hybrid Inflation

Abstract

We explore the upper bound on the tensor-to-scalar ratio $r$ in supersymmetric (F-term) hybrid inflation models with the gauge symmetry breaking scale set equal to the value $2.86\cdot 10^{16}\mathrm{GeV}$, as dictated by the unification of the MSSM gauge couplings. We employ a unique renormalizable superpotential and a quasi-canonical Kähler potential, and the scalar spectral index $n_s$ is required to lie within the two-sigma interval from the central value found by the Planck satellite. In a sizable region of the parameter space the potential along the inflationary trajectory is a monotonically increasing function of the inflaton, and for this case, $r\lesssim 2.9\cdot 10^{-4}$, while the spectral index running, $|d{n}_{\mathrm{s}}/d\ln k|$, can be as large as $0.01$. Ignoring higher order terms which ensure the boundedness of the potential for large values of the inflaton, the upper bound on $r$ is significantly larger, of order $0.01$, for subplanckian values of the inflaton, and $|d{n}_{\mathrm{s}}/d\ln k|\simeq 0.006$.

To appear in PLB

References in corpus (10)

• BICEP2 I: Detection Of B-mode Polarization at Degree Angular Scales
• Supersymmetric Hybrid Inflation with Non-Minimal Kahler potential
• More hilltop inflation models
• Hybrid inflation along waterfall trajectories
• Supersymmetric And Smooth Hybrid Inflation In The Light Of WMAP3
• Spontaneous B-L Breaking as the Origin of the Hot Early Universe
• Observable Gravity Waves from Supersymmetric Hybrid Inflation II
• Inflation in Supersymmetric SU(5)
• Basics of inflationary cosmology
• Killing the Straw Man: Does BICEP Prove Inflation at the GUT Scale?

Cited by in corpus (24)

• New Higgs Inflation in a No-Scale Supersymmetric SU(5) GUT
• Gravity Waves From Non-Minimal Quadratic Inflation
• Shift Symmetry and Higgs Inflation in Supergravity with Observable Gravitational Waves
• Shifted $\mu$-hybrid inflation, gravitino dark matter, and observable gravity waves
• Gravity Waves and Proton Decay in Flipped SU(5) Hybrid Inflation Model
• $\mu$-Hybrid Inflation with Low Reheat Temperature and Observable Gravity Waves
• From Hybrid to Quadratic Inflation With High-Scale Supersymmetry Breaking
• Simplified Smooth Hybrid Inflation in Supersymmetric SU(5)
• Kinetically Modified Non-Minimal Higgs Inflation in Supergravity
• Gravitational Waves, mu Term & Leptogenesis from B-L Higgs Inflation in Supergravity
• PeV-Scale SUSY and Cosmic Strings from F-term Hybrid Inflation
• Induced-Gravity GUT-Scale Higgs Inflation in Supergravity
• Probing the Supersymmetry-Mass Scale With F-term Hybrid Inflation
• $\mu$-Hybrid Inflation and Metastable Cosmic Strings in $\mathbf{SU}(3{)}_{\mathbf{c}}\times \mathbf{SU}(2{)}_{\mathbf{L}}\times \mathbf{SU}(2{)}_{\mathbf{R}}\times \mathbf{U}(1{)}_{\mathbf{B}-\mathbf{L}}$
• Variants of Kinetically Modified Non-Minimal Higgs Inflation in Supergravity
• BICEP2, the curvature perturbation and supersymmetry
• Radiative Symmetry breaking, Cosmic Strings and Observable Gravity Waves in $U(1{)}_R$ symmetric $SU(5)\times U(1{)}_{\chi }$
• Supersymmetric hybrid inflation with non-minimal coupling to gravity
• Quantum Smearing in Hybrid Inflation with Chaotic Potentials
• Supersymmetric Hybrid Inflation in Light of CMB Experiments and Swampland Conjectures
• Beginning of Universe through large field hybrid inflation
• GUT-scale inflation with sizeable tensor modes
• Axion, mu Term, and Supersymmetric Hybrid Inflation
• Kinetically Modified Non-Minimal Inflation With Exponential Frame Function