ipho-lean / lean_problems /Y2023.lean
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/-
Copyright (c) 2026 Humanize/Codex. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Authors: Humanize/Codex
-/
import Mathlib
/-!
Algebraic answer claims for the IPhO 2023 theory problems. The definitions
below isolate the official closed-form expressions; the named theorems expose
one answer statement for each requested subquestion.
-/
open scoped BigOperators
namespace Ipho20212023Archon.Problems.Y2023
noncomputable section
section Problem1
def brownianInitialVelocity (I0 M : ℝ) : ℝ := I0 / M
def brownianRelaxationTime (M gamma : ℝ) : ℝ := M / gamma
theorem IPhO_2023_1_A_1 (I0 M gamma : ℝ) :
(brownianInitialVelocity I0 M, brownianRelaxationTime M gamma) =
(I0 / M, M / gamma) := by
sorry
def collisionVelocity {ΞΉ : Type*} (s : Finset ΞΉ) (impulse time : ΞΉ β†’ ℝ)
(M tau t : ℝ) : ℝ :=
βˆ‘ i ∈ s, impulse i / M * Real.exp (-(t - time i) / tau)
def collisionTimeInRange (t ti : ℝ) : Prop := 0 < ti ∧ ti < t
theorem IPhO_2023_1_A_2 {ΞΉ : Type*} (s : Finset ΞΉ) (impulse time : ΞΉ β†’ ℝ)
(M tau t : ℝ) :
collisionVelocity s impulse time M tau t =
βˆ‘ i ∈ s, impulse i / M * Real.exp (-(t - time i) / tau) ∧
(βˆ€ i, collisionTimeInRange t (time i) ↔ 0 < time i ∧ time i < t) := by
sorry
def brownianMeanDisplacement : ℝ := 0
def discreteMeanSquareDisplacement (N : β„•) (C delta : ℝ) : ℝ :=
(N : ℝ) * C * delta ^ 2
def brownianMeanSquareDisplacement (C delta t : ℝ) : ℝ := C * delta * t
theorem IPhO_2023_1_B_1 (N : β„•) (C delta t : ℝ)
(ht : t = (N : ℝ) * delta) :
brownianMeanDisplacement = 0 ∧
discreteMeanSquareDisplacement N C delta = brownianMeanSquareDisplacement C delta t := by
sorry
def velocityVarianceDeltaExponent : β„€ := -1
def meanSquareTimeExponent : β„€ := 1
theorem IPhO_2023_1_B_2 :
(velocityVarianceDeltaExponent, meanSquareTimeExponent) = (-1, 1) := by
sorry
def positiveCrossingRate (n0 dn v delta : ℝ) : ℝ :=
((1 : ℝ) / 2) * n0 * v - ((1 : ℝ) / 4) * dn * v ^ 2 * delta
theorem IPhO_2023_1_C_1 (n0 dn v delta : ℝ) :
positiveCrossingRate n0 dn v delta =
((1 : ℝ) / 2) * n0 * v - ((1 : ℝ) / 4) * dn * v ^ 2 * delta := by
sorry
def negativeCrossingRate (n0 dn v delta : ℝ) : ℝ :=
((1 : ℝ) / 2) * n0 * v + ((1 : ℝ) / 4) * dn * v ^ 2 * delta
def diffusionFlux (C delta dn : ℝ) : ℝ := -((1 : ℝ) / 2) * dn * C * delta
def diffusionCoefficient (C delta : ℝ) : ℝ := ((1 : ℝ) / 2) * C * delta
theorem IPhO_2023_1_C_2 (C delta dn t : ℝ) :
diffusionFlux C delta dn = -((1 : ℝ) / 2) * dn * C * delta ∧
diffusionCoefficient C delta = ((1 : ℝ) / 2) * C * delta ∧
brownianMeanSquareDisplacement C delta t = 2 * diffusionCoefficient C delta * t := by
sorry
def electricConcentrationGradient (n kT Q E : ℝ) : ℝ := n / kT * Q * E
theorem IPhO_2023_1_C_3 (n kT Q E : ℝ) :
electricConcentrationGradient n kT Q E = n / kT * Q * E := by
sorry
def meanElectrophoreticVelocity (Q E gamma tau t : ℝ) : ℝ :=
Q * E / gamma * (1 - Real.exp (-t / tau))
def electrophoreticDrift (Q E gamma : ℝ) : ℝ := Q * E / gamma
theorem IPhO_2023_1_C_4 (Q E gamma tau t : ℝ) :
(meanElectrophoreticVelocity Q E gamma tau t, electrophoreticDrift Q E gamma) =
(Q * E / gamma * (1 - Real.exp (-t / tau)), Q * E / gamma) := by
sorry
def einsteinDiffusion (kT gamma : ℝ) : ℝ := kT / gamma
theorem IPhO_2023_1_C_5 (kT gamma : ℝ) :
einsteinDiffusion kT gamma = kT / gamma := by
sorry
def meanSquareAvogadroRelation (R T deltaT a eta NA : ℝ) : ℝ :=
R * T * deltaT / (3 * Real.pi * a * eta * NA)
def avogadroFromMSD (R T deltaT a eta msd : ℝ) : ℝ :=
R * T * deltaT / (3 * Real.pi * a * eta * msd)
def avogadroEstimate : ℝ := ((56 : ℝ) / 10) * (10 : ℝ) ^ 23
theorem IPhO_2023_1_D_1 (R T deltaT a eta NA msd : ℝ) :
meanSquareAvogadroRelation R T deltaT a eta NA =
R * T * deltaT / (3 * Real.pi * a * eta * NA) ∧
avogadroFromMSD R T deltaT a eta msd =
R * T * deltaT / (3 * Real.pi * a * eta * msd) ∧
avogadroEstimate = ((56 : ℝ) / 10) * (10 : ℝ) ^ 23 := by
sorry
def driftDiffusionMSD (u D t : ℝ) : ℝ := (u * t) ^ 2 + 2 * D * t
def driftDiffusionCrossoverTime (D u : ℝ) : ℝ := 2 * D / u ^ 2
theorem IPhO_2023_1_D_2 (u D t : ℝ) :
(driftDiffusionMSD u D t, driftDiffusionCrossoverTime D u) =
((u * t) ^ 2 + 2 * D * t, 2 * D / u ^ 2) := by
sorry
def runTumbleSmallMSD (D t : ℝ) : ℝ := 2 * D * t
def runTumbleIntermediateMSD (u0 t : ℝ) : ℝ := u0 ^ 2 * t ^ 2
def runTumbleLargeMSD (u0 delta0 t : ℝ) : ℝ := u0 ^ 2 * delta0 * t
theorem IPhO_2023_1_D_3 (D u0 delta0 t : ℝ) :
(runTumbleSmallMSD D t, runTumbleIntermediateMSD u0 t,
runTumbleLargeMSD u0 delta0 t) =
(2 * D * t, u0 ^ 2 * t ^ 2, u0 ^ 2 * delta0 * t) := by
sorry
def criticalCoagulationConcentration (B eps kT NA A q : ℝ) : ℝ :=
8 * B ^ 2 * eps ^ 3 * kT ^ 5 / (Real.exp 4 * NA * A ^ 2 * q ^ 6)
theorem IPhO_2023_1_E_1 (B eps kT NA A q : ℝ) :
criticalCoagulationConcentration B eps kT NA A q =
8 * B ^ 2 * eps ^ 3 * kT ^ 5 / (Real.exp 4 * NA * A ^ 2 * q ^ 6) := by
sorry
end Problem1
section Problem2
def symmetricNucleusOptimalA (aS aC : ℝ) : ℝ := 2 * aS / aC
def symmetricNucleusOptimalARounded : β„• := 50
theorem IPhO_2023_2_A_1 (aS aC : ℝ) :
(symmetricNucleusOptimalA aS aC, symmetricNucleusOptimalARounded) =
(2 * aS / aC, 50) := by
sorry
def massNumberTwoThirds (A : ℝ) : ℝ := Real.rpow A ((2 : ℝ) / 3)
def mostStableAtomicNumber (A aC asym : ℝ) : ℝ :=
(A / 2) / (1 + aC / (4 * asym) * massNumberTwoThirds A)
def goldStableAtomicNumberEstimate : β„• := 79
theorem IPhO_2023_2_A_2 (A aC asym : ℝ) :
(mostStableAtomicNumber A aC asym, goldStableAtomicNumberEstimate) =
((A / 2) / (1 + aC / (4 * asym) * Real.rpow A ((2 : ℝ) / 3)), 79) := by
sorry
def symmetricFissionCoefficient : ℝ :=
(Real.rpow (2 : ℝ) ((1 : ℝ) / 3) - 1) /
(1 - Real.rpow (2 : ℝ) (-(2 : ℝ) / 3))
def symmetricFissionCoefficientTwoSig : ℝ := (7 : ℝ) / 10
theorem IPhO_2023_2_A_3 :
(symmetricFissionCoefficient, symmetricFissionCoefficientTwoSig) =
((Real.rpow (2 : ℝ) ((1 : ℝ) / 3) - 1) /
(1 - Real.rpow (2 : ℝ) (-(2 : ℝ) / 3)), (7 : ℝ) / 10) := by
sorry
def neutronStarGravityCoefficient (hbarc mN R0 MP : ℝ) : ℝ :=
((3 : ℝ) / 5) * hbarc * mN ^ 2 / (R0 * MP ^ 2)
def neutronStarCriticalMassNumber (aV asym agrav : ℝ) : ℝ :=
Real.rpow ((asym - aV) / agrav) ((3 : ℝ) / 2)
def neutronStarGravityCoefficientEstimate : ℝ := (6 : ℝ) / (10 : ℝ) ^ 37
def neutronStarCriticalMassNumberEstimate : ℝ := (4 : ℝ) * (10 : ℝ) ^ 55
theorem IPhO_2023_2_B_1 (hbarc mN R0 MP aV asym agrav : ℝ) :
neutronStarGravityCoefficient hbarc mN R0 MP =
((3 : ℝ) / 5) * hbarc * mN ^ 2 / (R0 * MP ^ 2) ∧
neutronStarCriticalMassNumber aV asym agrav =
Real.rpow ((asym - aV) / agrav) ((3 : ℝ) / 2) ∧
(neutronStarGravityCoefficientEstimate, neutronStarCriticalMassNumberEstimate) =
((6 : ℝ) / (10 : ℝ) ^ 37, (4 : ℝ) * (10 : ℝ) ^ 55) := by
sorry
def freeFallClockFactor (dphi c : ℝ) : ℝ := 1 - dphi / c ^ 2
def freeFallClockDelay (dphi c tauI : ℝ) : ℝ := freeFallClockFactor dphi c * tauI
theorem IPhO_2023_2_C_1 (dphi c tauI : ℝ) :
freeFallClockDelay dphi c tauI = (1 - dphi / c ^ 2) * tauI := by
sorry
def shapiroDelay (G MWD c xN xE d : ℝ) : ℝ :=
2 * G * MWD / c ^ 3 * Real.log (4 * |xN| * xE / d ^ 2)
theorem IPhO_2023_2_C_2 (G MWD c xN xE d : ℝ) :
shapiroDelay G MWD c xN xE d =
2 * G * MWD / c ^ 3 * Real.log (4 * |xN| * xE / d ^ 2) := by
sorry
def shapiroDelaySwing (G MWD c eps : ℝ) : ℝ :=
2 * G * MWD / c ^ 3 * Real.log (4 / eps ^ 2)
theorem IPhO_2023_2_C_3 (G MWD c eps : ℝ) :
shapiroDelaySwing G MWD c eps =
2 * G * MWD / c ^ 3 * Real.log (4 / eps ^ 2) := by
sorry
def whiteDwarfMassRatioEstimate : ℝ := (1 : ℝ) / 2
theorem IPhO_2023_2_C_4 :
whiteDwarfMassRatioEstimate = (1 : ℝ) / 2 := by
sorry
def keplerAngularFrequencyExponent : ℝ := -(3 : ℝ) / 2
theorem IPhO_2023_2_C_5 :
keplerAngularFrequencyExponent = -(3 : ℝ) / 2 := by
sorry
inductive WaveProfile
| a
| b
| c
deriving DecidableEq, Repr
def chosenGravitationalWaveProfile : WaveProfile := WaveProfile.b
theorem IPhO_2023_2_C_6 :
chosenGravitationalWaveProfile = WaveProfile.b := by
sorry
end Problem2
section Problem3
def dropSurfaceEnergy (a gamma : ℝ) : ℝ := 4 * Real.pi * a ^ 2 * gamma
def mergedDropEnergyDifference (a gamma : ℝ) : ℝ :=
4 * Real.pi * (2 - Real.rpow (2 : ℝ) ((2 : ℝ) / 3)) * a ^ 2 * gamma
def mergedDropMass (a rho : ℝ) : ℝ := 8 * Real.pi * a ^ 3 * rho / 3
def mergedDropJumpSpeedSquared (k gamma rho a : ℝ) : ℝ :=
3 * (2 - Real.rpow (2 : ℝ) ((2 : ℝ) / 3)) * k * gamma / (rho * a)
def mergedDropJumpSpeed (k gamma rho a : ℝ) : ℝ :=
Real.sqrt (mergedDropJumpSpeedSquared k gamma rho a)
def mergedDropJumpSpeedEstimate : ℝ := (23 : ℝ) / 100
theorem IPhO_2023_3_A_1 (a gamma k rho : ℝ) :
mergedDropEnergyDifference a gamma =
4 * Real.pi * (2 - Real.rpow (2 : ℝ) ((2 : ℝ) / 3)) * a ^ 2 * gamma ∧
mergedDropMass a rho = 8 * Real.pi * a ^ 3 * rho / 3 ∧
(mergedDropJumpSpeed k gamma rho a, mergedDropJumpSpeedEstimate) =
(Real.sqrt (3 * (2 - Real.rpow (2 : ℝ) ((2 : ℝ) / 3)) *
k * gamma / (rho * a)), (23 : ℝ) / 100) := by
sorry
def hydrostaticPressure (P0 rho g z : ℝ) : ℝ := P0 - rho * g * z
theorem IPhO_2023_3_B_1 (P0 rho g z : ℝ) :
hydrostaticPressure P0 rho g z = P0 - rho * g * z := by
sorry
def horizontalPressureForce (rho g z1 z2 : ℝ) : ℝ :=
((1 : ℝ) / 2) * rho * g * (z2 ^ 2 - z1 ^ 2)
theorem IPhO_2023_3_B_2 (rho g z1 z2 : ℝ) :
horizontalPressureForce rho g z1 z2 =
((1 : ℝ) / 2) * rho * g * (z2 ^ 2 - z1 ^ 2) := by
sorry
def surfaceTensionHorizontalForce (gamma theta1 theta2 : ℝ) : ℝ :=
gamma * Real.cos theta1 - gamma * Real.cos theta2
theorem IPhO_2023_3_B_3 (gamma theta1 theta2 : ℝ) :
surfaceTensionHorizontalForce gamma theta1 theta2 =
gamma * Real.cos theta1 - gamma * Real.cos theta2 := by
sorry
def capillaryConservedQuantity (rho g gamma z theta : ℝ) : ℝ :=
((1 : ℝ) / 2) * rho * g * z ^ 2 + gamma * Real.cos theta
def capillaryDimensionlessExponent : β„• := 2
def capillaryLength (gamma rho g : ℝ) : ℝ := Real.sqrt (gamma / (rho * g))
theorem IPhO_2023_3_B_4 (rho g gamma z theta : ℝ) :
(capillaryConservedQuantity rho g gamma z theta, capillaryDimensionlessExponent,
capillaryLength gamma rho g) =
(((1 : ℝ) / 2) * rho * g * z ^ 2 + gamma * Real.cos theta, 2,
Real.sqrt (gamma / (rho * g))) := by
sorry
def capillarySurfaceSmallSlope (ell theta0 x : ℝ) : ℝ :=
-ell * Real.tan theta0 * Real.exp (-x / ell)
theorem IPhO_2023_3_B_5 (ell theta0 x : ℝ) :
capillarySurfaceSmallSlope ell theta0 x =
-ell * Real.tan theta0 * Real.exp (-x / ell) := by
sorry
def rodHorizontalForce (rho g gamma za zb thetaA thetaB : ℝ) : ℝ :=
((1 : ℝ) / 2) * rho * g * (zb ^ 2 - za ^ 2) +
gamma * (Real.cos thetaB - Real.cos thetaA)
theorem IPhO_2023_3_C_1 (rho g gamma za zb thetaA thetaB : ℝ) :
rodHorizontalForce rho g gamma za zb thetaA thetaB =
((1 : ℝ) / 2) * rho * g * (zb ^ 2 - za ^ 2) +
gamma * (Real.cos thetaB - Real.cos thetaA) := by
sorry
def rodAttractionForce (rho g z0 : ℝ) : ℝ := -((1 : ℝ) / 2) * rho * g * z0 ^ 2
theorem IPhO_2023_3_C_2 (rho g z0 : ℝ) :
rodAttractionForce rho g z0 = -((1 : ℝ) / 2) * rho * g * z0 ^ 2 := by
sorry
def midpointHeightBetweenRods (za xa ell : ℝ) : ℝ :=
2 * za / (Real.exp (xa / ell) + Real.exp (-xa / ell))
theorem IPhO_2023_3_C_3 (za xa ell : ℝ) :
midpointHeightBetweenRods za xa ell =
2 * za / (Real.exp (xa / ell) + Real.exp (-xa / ell)) := by
sorry
end Problem3
end
end Ipho20212023Archon.Problems.Y2023