Inflaton Entanglement
This research explores some interesting observable signatures that could come from initial state entanglement of the inflation.
1) Cosmological Consequences of Initial State Entanglement https://arxiv.org/abs/1408.6859
2) Modifications to Cosmological Power Spectra from Scalar-Tensor Entanglement and their Observational Consequences https://arxiv.org/abs/1605.01008
3) Cosmic Inflation: The Most Powerful Microscope in the Universe https://arxiv.org/abs/1806.00392
4) Non-Gaussianity from Entanglement During Inflation https://arxiv.org/abs/1902.07567
See also:
a) Generating Entangled Inflationary Quantum States https://arxiv.org/abs/1902.00521
b) Quantum Entanglement in Multi-field Inflation https://arxiv.org/abs/1805.09448