History Projection Operators
The key observation of the HPO formalism is to represent history propositions by projection operators on a history Hilbert space. This is where the name "History Projection Operator" (HPO) comes from.
For a homogeneous history we can use the tensor product to define a projector
where is the projection operator on that represents the proposition at time .
This is a projection operator on the tensor product "history Hilbert space"
Not all projection operators on can be written as the sum of tensor products of the form . These other projection operators are used to represent inhomogeneous histories by applying lattice operations to homogeneous histories.
Read more about this topic: HPO Formalism
Famous quotes containing the words history and/or projection:
“The history of persecution is a history of endeavors to cheat nature, to make water run up hill, to twist a rope of sand.”
—Ralph Waldo Emerson (1803–1882)
“My image is a statement of the symbols of the harsh, impersonal products and brash materialistic objects on which America is built today. It is a projection of everything that can be bought and sold, the practical but impermanent symbols that sustain us.”
—Andy Warhol (1928–1987)