CMB Feature Analysis Shows Primordial Oscillations Distinct from Post-Inflationary Energy Models
Theoretical study distinguishes primordial from post-inflationary CMB features via PCA and likelihood methods. No significant degeneracies found in representative models. Methods can extend to more realistic signals.
The paper examines two classes of scale-dependent signals: primordial features limited to sharp and resonant forms, and post-inflationary effects from simplified exotic energy injection and early dark energy. Principal component analysis on the most significant modes reveals no substantial degeneracies between the classes, while Bayesian posteriors remain stable whether models are fit individually or jointly. This separation arises because primordial oscillations allow arbitrary frequency and running, whereas the post-inflationary cases alter background expansion or thermodynamics in patterns lacking that flexibility.
Sources (2)
- [1]Primary Source(https://arxiv.org/abs/2611.08585)
- [2]Supporting Source(https://arxiv.org/abs/2305.07047)