False vacuum energy dominated inflation with large $r$ and the importance of ${\kappa }_s$

Abstract

We investigate to which extent and under which circumstances false vacuum energy ($V_0$) dominated slow-roll inflation is compatible with a large tensor-to-scalar ratio $r=O(0.1)$, as indicated by the recent BICEP2 measurement. With $V_0$ we refer to a constant contribution to the inflaton potential, present before a phase transition takes place and absent in the true vacuum of the theory, like e.g. in hybrid inflation. Based on model-independent considerations, we derive an upper bound on the possible amount of $V_0$ domination and highlight the importance of higher-order runnings of the scalar spectral index (beyond ${\alpha }_s$) in order to realise scenarios of $V_0$ dominated inflation. We study the conditions for $V_0$ domination explicitly with an inflaton potential reconstruction around the inflaton field value 50 e-folds before the end of inflation, taking into account the present observational data. To this end, we provide the up-to-date parameter constraints within $\Lambda$CDM + $r$ + ${\alpha }_s$ + ${\kappa }_s$ using the cosmological parameter estimation code Monte Python together with the Boltzmann code CLASS.

arXiv comment16 pages, 5 figures; v2: matches publication in JCAP

References in corpus (30)

• The Cosmic Linear Anisotropy Solving System (CLASS) II: Approximation schemes
• Particle Physics Models of Inflation and the Cosmological Density Perturbation
• BICEP2 I: Detection Of B-mode Polarization at Degree Angular Scales
• Encyclopaedia Inflationaris
• Reconstructing the Inflaton Potential --- an Overview
• Conservative Constraints on Early Cosmology: an illustration of the Monte Python cosmological parameter inference code
• Formalising the Slow-Roll Approximation in Inflation
• Particle physics models of inflation and curvaton scenarios
• Particle production during inflation and gravitational waves detectable by ground-based interferometers
• Toward an Understanding of Foreground Emission in the BICEP2 Region
• Generalised constraints on the curvature perturbation from primordial black holes
• The Spectrum of Density Perturbations produced during Inflation to Leading Order in a General Slow-Roll Approximation
• Blue Tensor Spectrum from Particle Production during Inflation
• New Sources of Gravitational Waves during Inflation
• Non-Bunch-Davies Initial State Reconciles Chaotic Models with BICEP and Planck
• Observable gravitational waves from inflation with small field excursions
• Generalized Slow Roll for Large Power Spectrum Features
• Short Distance Physics and the Consistency Relation for Scalar and Tensor Fluctuations in the Inflationary Universe
• Cosmic Microwave Background Observables of Small Field Models of Inflation
• Scale Dependent Spectral Index in Slow Roll Inflation
• Did BICEP2 see vector modes? First B-mode constraints on cosmic defects
• Can topological defects mimic the BICEP2 B-mode signal?
• Can primordial magnetic fields be the origin of the BICEP2 data?
• The Knotted Sky II: Does BICEP2 require a nontrivial primordial power spectrum?
• Testing Hybrid Natural Inflation with BICEP2
• A model-independent fit to Planck and BICEP2 data
• From Hybrid to Quadratic Inflation With High-Scale Supersymmetry Breaking
• Bogoliubov Excited States and the Lyth Bound
• Clearing the Brush: The Last Stand of Solo Small Field Inflation
• Large tensor spectrum of BICEP2 in the natural SUSY hybrid model

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• Constraints on the reheating temperature from sizable tensor modes
• Bound on largest $r\lesssim 0.1$ from sub-Planckian excursions of inflaton