Preheating after Small-Field Inflation

Abstract

Whereas preheating after chaotic and hybrid inflation models has been abundantly studied in the literature, preheating in small field inflation models, where the curvature of the inflaton potential is negative during inflation, remains less explored. In these models, a tachyonic instability at the end of inflation leads to a succession of exponentially large increases and \emph{decreases} of the inflaton fluctuations as the inflaton condensate oscillates around the minimum of its potential. The net effect is a competition between low-momentum modes which grow and decrease significantly, and modes with higher momenta which grow less but also decrease less. We develop an analytical description of this process, which is analogous to the quantum mechanical problem of tunneling through a volcano-shaped potential. Depending on the parameters, preheating may be so efficient that it completes in less than one oscillation of the inflaton condensate. Preheating after small field inflation may also be followed by a long matter-dominated stage before the universe thermalizes, depending on the energy scale of inflation and the details of the inflaton interactions. Finally, another feature of these models is that the spectrum of the inflaton fluctuations at the end of preheating may be peaked around the Hubble scale. In fact, because preheating starts when the second slow-roll parameter $|\eta |$ becomes of order unity while the first slow-roll parameter $\epsilon$ is still much smaller than one, the universe is still inflating during preheating and the modes amplified by the initial tachyonic instability leave the Hubble radius. This may lead to an abundant production of primordial black holes and gravitational waves with frequencies today which are naturally small enough to fall into the range accessible by high-sensitivity interferometric experiments.

34 pages, 16 figures. v2: 1 ref. added, accepted for publication in Phys.Rev.D

References in corpus (16)

• String Cosmology: A Review
• Theory and Numerics of Gravitational Waves from Preheating after Inflation
• Gauge invariant MSSM inflaton
• A Gravitational Wave Background from Reheating after Hybrid Inflation
• Gravitational Wave Production At The End Of Inflation
• A stochastic background of gravitational waves from hybrid preheating
• Gravitational Waves from Abelian Gauge Fields and Cosmic Strings at Preheating
• Non-Gaussian Spikes from Chaotic Billiards in Inflation Preheating
• Magnetic field production during preheating at the electroweak scale
• More hilltop inflation models
• Lattice calculation of non-Gaussianity from preheating
• DEFROST: A New Code for Simulating Preheating after Inflation
• Primordial magnetic fields from preheating at the electroweak scale
• Non-Gaussianity from massless preheating
• Black hole production in tachyonic preheating
• Gravitational Waves from the Non-Perturbative Decay of Condensates along Supersymmetric Flat Directions

Cited by in corpus (29)

• Cosmological Backgrounds of Gravitational Waves and eLISA/NGO: Phase Transitions, Cosmic Strings and Other Sources
• Production of Purely Gravitational Dark Matter
• The ALP miracle: unified inflaton and dark matter
• Oscillons from String Moduli
• Primordial black hole tower: Dark matter, earth-mass, and LIGO black holes
• The ALP miracle revisited
• Gravitational wave forest from string axiverse
• Light Dark Matter from Inflaton Decay
• Chaotic Inflation with a Fractional Power-Law Potential in Strongly Coupled Gauge Theories
• What can we learn from the stochastic gravitational wave background produced by oscillons?
• ALP inflation and Big Bang on Earth
• Emerging chromo-natural inflation
• Linear Growth of Structure in the Symmetron Model
• Curvature perturbation spectra from waterfall transition, black hole constraints and non-Gaussianity
• The Fate of Dense Scalar Stars
• Properties of oscillons in hilltop potentials: energies, shapes, and lifetimes
• Hill crossing during preheating after hilltop inflation
• Impact of other scalar fields on oscillons after hilltop inflation
• Asymmetric Dark Matter, Inflation and Leptogenesis from B-L Symmetry Breaking
• Dynamical Fractional Chaotic Inflation -- Dynamical Generation of a Fractional Power-Law Potential for Chaotic Inflation
• Parametric resonance after hilltop inflation caused by an inhomogeneous inflaton field
• Electroweak Vacuum Metastability and Low-scale Inflation
• The Linear Regime of Tachyonic Preheating
• Computation of Gravitational Particle Production Using Adiabatic Invariants
• Hilltop inflation with preinflation from coupling to matter fields
• Variable Inflaton Equation of State and Reheating
• Non-thermal Leptogenesis after Majoron Hilltop Inflation
• $\mathcal{O}(10)M_{\odot }$ primordial black holes and string axion dark matter
• Loop corrections to primordial fluctuations from inflationary phase transitions