 Solution

ID: past-exam-of-the-mathematics-course-of-the-university-of-cambridge/2025/ii/paper-2/15c/d/i/solution

Codex  0 Created 2026-09-24 Updated 2026-09-25

With the positive-exponent convention,

QFT_{M} ∣ x ⟩ = \frac{1}{M} u = 0 \sum M - 1 e^{2 πi xu / M} ∣ u ⟩ .

The opposite sign convention is equivalent after conjugating all Fourier phases.

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