Qiskit, Quantum Computing, Quantum Simulation.
This average or expectation should ideally equal the value we get upon calculating <x|K|x>, but because of noise, we might not get the exact number. The fact that the ideal expectation value is <x|K|x> can seen by writing K as m1|m1><m1| + m2|m2><m2|+ m3|m3><m3|……..where m1, m2, m3 and so on, are