  The field theoretic wavefunction in cosmological spacetimes has received much
attention as a fundamental object underlying the generation of primordial
perturbations in our universe. Assuming an initial Bunch-Davies state, unitary
time evolution implies an infinite set of cutting rules for the wavefunction to
all orders in perturbation theory, collectively known as the cosmological
optical theorem. In this work, we generalise these results to the case of
Bogoliubov initial states, accounting for both parity-even and parity-odd
interactions. We confirm our findings in a few explicit examples, assuming
IR-finite interactions. In these examples, we preserve scale invariance by
adiabatically turning on interactions in the infinite past rather than imposing
a Bogoliubov state at some finite initial time. Finally, we give a prescription
for computing Bogoliubov wavefunction coefficients from the corresponding
Bunch-Davies coefficients for both n-point contact and four-point exchange
diagrams.
