Quantum Field Theory In Curved Spacetime: Quant... -

To relate the perspectives of different observers or the state of fields at different times in an expanding universe, physicists use : Field Decomposition : A scalar field is expanded into a set of basis modes with creation and annihilation operators

: Because global constructs like Fourier transforms are unavailable, QFTCS must be formulated locally using quantum field operators rather than particle counts. 2. Mathematical Framework: Bogoliubov Transformations Quantum Field Theory in Curved Spacetime: Quant...

) will contain a non-zero number of particles according to the second observer. 3. Key Phenomena To relate the perspectives of different observers or