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arXiv · 2404.12655

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

Shi Pan·Yong Cai·Yun-Song Piao
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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.

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Shi Pan, Yong Cai, Yun-Song Piao. 2024-04-19. Climbing over the potential barrier during inflation via null energy condition violation. https://doi.org/10.1140/epjc%2Fs10052-024-13340-1

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