5 papers
A Bogoliubov-ratio framework for quantum-information diagnostics of time-dependent two-mode Boson Hamiltonian
Shi-Cheng Liu, Lei-Hua Liu, Bichu Li +2
We present a compact and unified framework for quantum-information diagnostics of time-dependent two-mode bosonic systems based on the Bogoliubov ratio $λ_k(η) \equiv β_k(η)/α…
Quantum-information diagnostics of cosmological perturbations with nontrivial sound speed in inflation
Shi-Cheng Liu, Lei-Hua Liu, Bichu Li +2
In this work, we systematically investigate the quantum-information diagnostics of cosmological perturbations with a nontrivial sound speed, utilizing a normalized open two-mode sq…
Non-minimally Coupled Running Curvaton for DESI-preferred Dynamical Dark Energy and Hubble Tension
Bichu Li, Lei-Hua Liu
Recent DESI 2025 results have renewed interest in dynamical dark energy models with phantom crossing. In this work, we extend the running curvaton scenario by introducing a non-min…
A quantum information method for early universe with non-trivial sound speed
Shi-Cheng Liu, Lei-Hua Liu, Bichu Li +2
Many quantum gravitational frameworks, such as DBI inflation, k-essence, and effective field theories obtained by integrating out heavy modes, can lead to a non-trivial sound speed…
Microlensing of dark matter models in the Milky Way
Bichu Li, Chan-Yu Tang, Zhuo-Ran Huang +1
We investigate constraints on the abundance of primordial black holes (PBHs) as dark matter (DM) candidates using five years of microlensing data from the OGLE survey. While the ma…