Study of the Quartic Anharmonic Oscillator Using the System's Wave Function Expansion in the Oscillator Basis

V. A. Babenko, A. V. Nesterov

The quantum quartic anharmonic oscillator with the Hamiltonian $H=\frac{1}{2}\left(p^2+x^2\right)+\lambda x^4$ is a classical and fundamental model that plays a key role in variou…