TRANSLATION-INVARIANT QUASI-FREE STATES AND BOGOLYUBOV TRANSFORMATIONS.

IMPLEMENTING THE BOGOLYUBOV TRANSFORMATIONS

Translation invariant quasi-free states and Bogoliubov transformations

TRANSLATION-INVARIANT GROUND STATES FOR THE CHUI–WEEKS MODEL WITH FOUR SPIN STATES ON A CAYLEY TREE OF ORDER TWO

The invariant quasi-free states

THREE-NUCLEON MATRIX ELEMENTS IN TRANSLATION-INVARIANT OSCILLATOR STATES.

Quasi-free states of the C.C.R.—Algebra and Bogoliubov transformations