Four-body (an)harmonic oscillator in $d$-dimensional space: $S$-states, (quasi)-exact-solvability, hidden algebra $sl(7)$

M. A. Escobar-Ruiz, Alexander V. Turbiner, Willard Miller

As a generalization and extension of our previous paper {\it J. Phys. A: Math. Theor. 53 055302} \cite{AME2020}, in this work we study a quantum 4-body system in ${\mathbb{R}}^d$ ($d…