Improved DHOST Genesis

Zhu, Mian; Zheng, Yunlong

doi:10.48550/arxiv.2109.05277

Cited by 1 publication

(1 citation statement)

References 63 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The NEC is a fundamental principle in general relativity, stating that for any null vector, the contraction with the energy-momentum tensor yields a non-negative value. Nevertheless, scenarios that involve NEC violation have been conjectured to account for a range of early Universe phenomena, including the inflationary epoch and the genesis of primordial black holes [25][26][27][28][29][30][31][32]; see, for example, the review by [21]. Advances in modified gravity theories, especially within the framework of "beyond Horndeski" models [33][34][35][36][37][38][39], have shown that stable NEC violations are theoretically feasible, circumventing the issue of pathological instabilities.…”

Section: Introductionmentioning

confidence: 99%

Constraints on inflation with null energy condition violation from advanced LIGO and advanced Virgo's first three observing runs

Chen,

Liu

2024

J. Cosmol. Astropart. Phys.

View full text Add to dashboard Cite

The null energy condition (NEC) is a cornerstone of general relativity, and its violation could leave observable imprints in the cosmic gravitational wave spectrum. Theoretical models suggest that NEC violations during inflation can amplify the primordial tensor power spectrum, leading to distinct features in the stochastic gravitational wave background (SGWB). In this work, we search for these NEC-violating signatures in the SGWB using data from Advanced LIGO and Advanced Virgo's first three observing runs. Our analysis reveals no statistically significant evidence of such signals, allowing us to place stringent upper limits on the tensor power spectrum amplitude, P T,2, during the second inflationary stage. Specifically, we find that P T,2 ≲ 0.15 at a 95% confidence level. Notably, this upper limit is consistent with constraints derived from pulsar timing array observations, reinforcing the hypothesis that NEC violations during inflation could explain the signal detected by pulsar timing arrays. Our findings contribute to a deeper understanding of the early Universe and highlight the potential of current and future gravitational wave experiments in probing the physics of inflation and NEC violations.

show abstract