Climbing over the potential barrier during inflation via null energy condition violation

Abstract

The violation of the null energy condition (NEC) may play a crucial role in enabling a scalar field to climb over high potential barriers, potentially significant in the very early universe. We propose a single-field model where the universe sequentially undergoes a first stage of slow-roll inflation, NEC violation, and a second stage of slow-roll inflation. Through the NEC violation, the scalar field climbs over high potential barriers, leaving unique characteristics on the primordial gravitational wave power spectrum, including a blue-tilted nature in the middle-frequency range and diminishing oscillation amplitudes at higher frequencies. Additionally, the power spectrum exhibits nearly scale-invariant behavior on both large and small scales.

27 pages, 15 figures; referencees added, published in EPJC

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Cited by in corpus (4)

• Obviating PBH overproduction for SIGWs generated by Pulsar Timing Arrays in loop corrected EFT of bounce
• Tomography of flavoured leptogenesis with primordial blue gravitational waves
• Null energy condition violation and beyond Horndeski physics in light of DESI DR2 data
• Gravitational Waves from Primordial Black Holes formed by Null Energy Condition Violation during Inflation