theorem
proved
amplitude_modulus_bridge
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IndisputableMonolith.Measurement.C2ABridge on GitHub at line 196.
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193 simpa using hWeight
194
195/-- Amplitude bridge modulus: |𝒜| = exp(-A) -/
196theorem amplitude_modulus_bridge (rot : TwoBranchRotation) (φ : ℝ) :
197 ‖pathAmplitude (pathFromRotation rot) φ‖ = Real.exp (- rateAction rot) := by
198 unfold pathAmplitude
199 have hExpReal :
200 ‖Complex.exp (-(pathAction (pathFromRotation rot)) / 2)‖ =
201 Real.exp (-(pathAction (pathFromRotation rot)) / 2) := by
202 simpa using Complex.norm_exp_ofReal (-(pathAction (pathFromRotation rot)) / 2)
203 have hExpI :
204 ‖Complex.exp (φ * Complex.I)‖ = 1 := by
205 simpa using Complex.norm_exp_ofReal_mul_I φ
206 have hAction :
207 -(pathAction (pathFromRotation rot)) / 2 = - rateAction rot := by
208 have h := measurement_bridge_C_eq_2A rot
209 calc
210 -(pathAction (pathFromRotation rot)) / 2
211 = -(2 * rateAction rot) / 2 := by simpa [h]
212 _ = - rateAction rot := by ring
213 calc
214 ‖Complex.exp (-(pathAction (pathFromRotation rot)) / 2)
215 * Complex.exp (φ * Complex.I)‖
216 = ‖Complex.exp (-(pathAction (pathFromRotation rot)) / 2)‖ *
217 ‖Complex.exp (φ * Complex.I)‖ := by simpa using norm_mul _ _
218 _ = Real.exp (-(pathAction (pathFromRotation rot)) / 2) * 1 := by
219 simpa [hExpReal, hExpI]
220 _ = Real.exp (- rateAction rot) := by
221 simpa [hAction]
222
223end Measurement
224end IndisputableMonolith