Cherenkov in the Sky: Measuring the Sound Speed of Primordial Scalar Fluctuations
arXiv:1904.05589 · doi:10.1103/PhysRevD.100.023520
Abstract
We consider production of additional relativistic particles coupled to the inflaton. We show that the imprints of these particles on the spectrum of primordial perturbations can be used for the direct measurement of the speed of sound of scalar perturbations, regardless of the mechanism of the production of this species. We study a model where these relativistic localized sources are decay products of heavier particles generated via a resonance mechanism. These particles emit in-phase inflaton particles which interfere constructively on the the so-called sound boom, leading to an "inflationary Cherenkov effect". The resulting shock waves lead to distinctive patterns on the temperature anisotropies of the cosmic microwave background. Moreover, we show that the model predicts unique features on the power spectrum of curvature perturbation and sizeable flattened non-gaussianity for a suitable range of parameters.
arXiv comment18 pages, 3 figures
References in corpus (26)
- Towards the Theory of Reheating After Inflation
- k-Inflation
- Perturbations in k-inflation
- The Effective Field Theory of Inflation
- DBI in the Sky
- A Joint Analysis of BICEP2/Keck Array and Planck Data
- Scalar Speed Limits and Cosmology: Acceleration from D-cceleration
- Planck 2015 results. XVII. Constraints on primordial non-Gaussianity
- Non-Gaussianities in Single Field Inflation and their Optimal Limits from the WMAP 5-year Data
- Gauge Field Production in Axion Inflation: Consequences for Monodromy, non-Gaussianity in the CMB, and Gravitational Waves at Interferometers
- Probing Planckian physics: resonant production of particles during inflation and features in the primordial power spectrum
- On the consistency relation of the 3-point function in single field inflation
- On Loops in Inflation
- Multi-Throat Brane Inflation
- Productive Interactions: heavy particles and non-Gaussianity
- Blue Tensor Spectrum from Particle Production during Inflation
- Particle Production During Inflation: Observational Constraints and Signatures
- Large non-Gaussianities in the Effective Field Theory Approach to Single-Field Inflation: the Bispectrum
- Effects of particle production during inflation
- Large non-Gaussianities in the Effective Field Theory Approach to Single-Field Inflation: the Trispectrum
- A Naturally Large Four-Point Function in Single Field Inflation
- On Features and Nongaussianity from Inflationary Particle Production
- Gravitational Waves and the Scale of Inflation
- From Wires to Cosmology
- Primordial Statistical Anisotropies: The Effective Field Theory Approach
- Stochastic Particle Production in a de Sitter Background