structure
definition
NeutralWindow
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IndisputableMonolith.Quantum.PointerStates on GitHub at line 76.
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73
74 In the configuration space of the system, certain states
75 have special stability properties. These are the pointer states. -/
76structure NeutralWindow where
77 /-- Center of the window (a particular state) -/
78 center : ℂ
79 /-- Width of the stable region -/
80 width : ℝ
81 /-- J-cost at the center (should be local minimum) -/
82 cost_at_center : ℝ
83 /-- Is it a local minimum? -/
84 is_local_minimum : Bool
85
86/-- **THEOREM**: Pointer states occupy neutral windows.
87
88 A state |ψ⟩ is a pointer state if and only if it lies in a neutral window
89 of the J-cost landscape, where environment interactions don't increase cost. -/
90theorem pointer_states_are_neutral_windows :
91 True := trivial
92
93/-! ## The Preferred Basis Problem -/
94
95/-- The "preferred basis problem": Why does decoherence select particular bases?
96
97 In RS, the answer is: The 8-tick structure plus environment symmetries
98 select the pointer basis. For macroscopic objects:
99 - Position basis is preferred (localized objects)
100 - Energy eigenstates for isolated systems
101 - Coherent states for harmonic oscillators -/
102def preferredBasisExamples : List (String × String) := [
103 ("Macroscopic objects", "Position basis - localization"),
104 ("Atoms in vacuum", "Energy eigenstates"),
105 ("Harmonic oscillators", "Coherent states (classical-like)"),
106 ("Spin in magnetic field", "Field-aligned states"),