Meaning and magnitude of the reduced density matrix cumulants

► Cumulants of high ranks stay large in cases with strong left-right correlation. ► In single reference cases, cumulant norms decline roughly exponentially with the rank. ► When the wave function has electron-hole symmetry, odd-rank cumulants vanish. ► A cumulant of rank n describes correlation between occupation numbers of n orbitals. ► We congratulate Debashis Mukherjee and wish him all the best to his 65th birthday!