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arXiv · 2603.21762

Inflationary phase transitions in the early Universe: A Bayesian study with space-based gravitational-wave detectors

Qingyuan Liang·Chen Yang·Haipeng An·Huai-Ke Guo
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Abstract

Inflationary phase transitions can generate a stochastic gravitational-wave background that probes primordial physics. We study the detectability and parameter reconstruction of such a signal with a space-based gravitational-wave detector. Using a Taiji-like mission as a benchmark, we construct a realistic data-analysis framework that includes instrumental noise, astrophysical foregrounds and backgrounds, and the $A$, $E$, and $T$ time-delay interferometry channels. The target signal is described in a minimal, model-independent form and analyzed using both Fisher-matrix forecasts and Bayesian inference with nested sampling. We quantify detection significance and parameter-recovery thresholds, showing that, while detection is achievable at moderate signal-to-noise ratios, stronger signals provide more reliable parameter reconstruction. These results offer a realistic assessment of the capability of future space-based missions to probe inflationary phase transitions through stochastic gravitational radiation.

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Qingyuan Liang, Chen Yang, Haipeng An, Huai-Ke Guo. 2026-03-23. Inflationary phase transitions in the early Universe: A Bayesian study with space-based gravitational-wave detectors. https://doi.org/10.1103/h3mz-cckw

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