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Woit · 2025-10-20
已登记出处中的最早位置：§37.1 · en。
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§37.1 · en · machine_draft · machine-draft-not-reviewed
One does however want to be able to discuss states with well-defined positions, in order to describe amplitudes for particle propagation, and to introduce local interactions between particles. One approach is to try and define operators corresponding to creation or annihilation of a particle at a fixed position, by taking a Fourier transform of the annihilation and creation operators for momentum eigenstates. Quantum fields could be defined as