Consequences of inflationary coherent/squeezed/cat states for cosmology and CMB detection

Determine the consequences of quadratic quantum inflationary fluctuations modeled as time‑dependent oscillator coherent, squeezed, and Schrödinger‑cat states for cosmological evolution and for the detection of Cosmic Microwave Background (CMB) fluctuations, including the observable implications of such states.

Background

The paper develops a framework based on the Minimum Group Representation Principle (MGRP) and the Metaplectic group Mp(n) to describe quantum spacetime, entanglement, and generalized (Berry-type) geometrical phases. Within this approach, the authors analyze inflation and cosmological perturbations, expressing Berry phases in terms of observables such as the scalar and tensor spectral indices and the tensor-to-scalar ratio.

They also interpret quadratic quantum inflationary fluctuations using the theory of time-dependent oscillators, relating them to coherent, squeezed, and Schrödinger-cat states. While the formalism is established, the concrete impact of these specific quantum states on cosmological evolution and on measurable CMB fluctuations is explicitly stated as unclear, motivating a precise determination of their observational consequences.

References

Till now it remains unclear what are the consequences of such states for the cosmological evolution and the detection of CMB fluctuations, but hopefully such results will emerge from these investigations.

— Entanglement and Generalized Berry Geometrical Phases in Quantum Gravity  (2408.11078 - Cirilo-Lombardo et al., 2024) in Section 1, Introduction and Results

However, since non-linear dynamics may couple $\mathcal{R}$ to its conjugate momentum, whether the stochastic description of $n$-point functions of $\mathcal{R}$ requires large squeezing beyond linear theory requires further study.

— Classical Noise in Transient USR Inflation  (2609.19478 - N. et al., 16 Sep 2026) in Section 5, Conclusion