inductive
definition
Statistics
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IndisputableMonolith.QFT.SpinStatistics on GitHub at line 161.
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depends on
used by
-
boson_rotation_phase_pos_one -
exchange_sign_boson -
piInPhysics -
quasi_charge_decreasing -
summary -
boson_symmetric -
eight_ticks_full_cycle -
exchangePhase -
spin_statistics_boson -
spin_statistics_fermion -
statisticsFromSpin -
certificateWithinTolerance -
bayesianFilteringCert_holds -
cert_inhabited -
vfeCert_holds -
stateProbability -
classical_limit
formal source
158/-! ## Particle Statistics Classification -/
159
160/-- Particle statistics type. -/
161inductive Statistics where
162 | fermiDirac
163 | boseEinstein
164deriving DecidableEq, Repr
165
166/-- Determine statistics from spin. -/
167def statisticsFromSpin (s : Spin) : Statistics :=
168 if s.isHalfInteger then Statistics.fermiDirac else Statistics.boseEinstein
169
170/-- **THEOREM (Spin-Statistics)**: Half-integer spin implies Fermi-Dirac statistics. -/
171theorem spin_statistics_fermion (s : Spin) (h : s.isHalfInteger) :
172 statisticsFromSpin s = Statistics.fermiDirac := by
173 simp [statisticsFromSpin, h]
174
175/-- **THEOREM (Spin-Statistics)**: Integer spin implies Bose-Einstein statistics. -/
176theorem spin_statistics_boson (s : Spin) (h : s.isInteger) :
177 statisticsFromSpin s = Statistics.boseEinstein := by
178 simp [statisticsFromSpin]
179 intro h'
180 exact absurd (And.intro h h') (Spin.int_half_exclusive s)
181
182/-! ## Exchange Symmetry -/
183
184/-- Symmetry type for wavefunction under particle exchange. -/
185inductive ExchangeSymmetry where
186 | symmetric -- ψ(1,2) = +ψ(2,1)
187 | antisymmetric -- ψ(1,2) = -ψ(2,1)
188deriving DecidableEq, Repr
189
190/-- Determine exchange symmetry from spin. -/
191def exchangeSymmetryFromSpin (s : Spin) : ExchangeSymmetry :=