Hello, I've been reading a book on QFT (specifically, Atchison and Hey) and they say that a classical field can be expanded into an integral of harmonic oscillators. When you quantize the scalar field [itex]\phi[/itex], it becomes an operator. Now, this is an infinite number of quantum oscillators. Do these correspond to particles? Of course, you can also write out the Hamiltonian in this way; in other words, does the energy of the field equal the sum of all the energies of these particles?