8 problems

Entanglement-density conjecture. The entanglement per atom does not vanish in the thermodynamic limit.

Let $\gamma$ be the Stark coupling and $\omega$ the photon frequency in the Rabi–Stark model. The critical values are $\gamma=\pm\omega$. Critical-point conjecture. The values…

The discussion concerns a non-Hermitian Hamiltonian with real spectrum that governs unitary evolution after the Hilbert space of states is appropriately amended. Bender–Boettcher c…

In a non-Hermitian but hermitizable quantum system, let $H$ be a Hamiltonian equipped with a metric operator $\Theta$ defining the inner product…

The original quantum Rabi model describes a two-level system coupled to a quantum oscillator. An excited-state quantum phase transition is a transition at a critical energy, charac…

The quantum Rabi–Stark model is the quantum Rabi model augmented by a nonlinear coupling between the two-level system and the oscillator; its Stark coupling strength can be tuned i…

Consider cosmological scenarios involving successive Big Bangs, including the alternatives of “nothing before Big Bang” and cyclic repetition of Big Bangs. The Darwin-like evolutio…

Consider the classical Hamiltonian … with coupling parameters $\lambda=\frac{kN}{2\epsilon}$ and $\beta=\frac{\mu}{\epsilon}$. Its fixed points are determined by…