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▲✐♣s❝❤✐t③✲❑✐❧❧✐♥❣ ❝✉r✈❛t✉r❡s ♦❢ ❡①❝✉rs✐♦♥ s❡ts ❢♦r ✷❉ r❛♥❞♦♠ ✜❡❧❞s ❍❡r♠✐♥❡ ❇✐❡r♠é✱ ▲▼❆✱ ❯♥✐✈❡rs✐t② ♦❢ P♦✐t✐❡rs ▼❛r❝❤✱ ✶✷t❤ ✷✵✶✾✱ ■❍P✱ P❛r✐s

❞❡❢❛✉❧t ❈♦❧❧❛❜♦r❛t✐♦♥ ❆❣♥ès ❉❡s♦❧♥❡✉① ✭❈◆❘❙✱ ❈▼▲❆✱ ❊◆❙ P❛r✐s✲❙❛❝❧❛②✮ ❊❧❡♥❛ ❉✐ ❇❡r♥❛r❞✐♥♦ ✭❈◆❆▼✱ P❛r✐s✮ ❈é❧✐♥❡ ❉✉✈❛❧ ✭▼❆P✺✱ ❯♥✐✈❡rs✐té P❛r✐s ❉❡s❝❛rt❡s✮ ❆♥♥❡ ❊str❛❞❡ ✭▼❆P✺✱ ❯♥✐✈❡rs✐té P❛r✐s ❉❡s❝❛rt❡s✮

❞❡❢❛✉❧t ❖✉t❧✐♥❡s ✶ ▼♦t✐✈❛t✐♦♥ ✿ ❙❤♦t ♥♦✐s❡ r❛♥❞♦♠ ✜❡❧❞s ❙❤♦t ♥♦✐s❡ r❛♥❞♦♠ ✜❡❧❞s ❊①❝✉rs✐♦♥ s❡ts ✿ ❡①❛♠♣❧❡s ✷ ▲✐♣s❝❤✐t③ ❑✐❧❧✐♥❣ ❈✉r✈❛t✉r❡s ❢♦r ❡①❝✉rs✐♦♥ s❡ts ▲✐♣s❝❤✐t③✲❑✐❧❧✐♥❣ ❝✉r✈❛t✉r❡s ❛♥❞ ❞❡♥s✐t✐❡s ❈❛s❡ ♦❢ s♠♦♦t❤ ❞❡t❡r♠✐♥✐st✐❝ ❢✉♥❝t✐♦♥s ❲❡❛❦ ❢♦r♠✉❧❛ ❢♦r st❛t✐♦♥❛r② r❛♥❞♦♠ ✜❡❧❞ ✸ ❊①❛♠♣❧❡s ♦❢ st❛t✐♦♥❛r② ✐s♦tr♦♣✐❝ r❛♥❞♦♠ ✜❡❧❞s ●❛✉ss✐❛♥ r❛♥❞♦♠ ✜❡❧❞s ❈❤✐✷ r❛♥❞♦♠ ✜❡❧❞s ❙t✉❞❡♥t r❛♥❞♦♠ ✜❡❧❞s ❙❤♦t ♥♦✐s❡ r❛♥❞♦♠ ✜❡❧❞s ✹ ❊①❛♠♣❧❡ ♦❢ r❡❛❧ ❞❛t❛

❞❡❢❛✉❧t ▼♦t✐✈❛t✐♦♥ ✿ ❙❤♦t ♥♦✐s❡ r❛♥❞♦♠ ✜❡❧❞s ❆ ✭P♦✐ss♦♥✮ s❤♦t ♥♦✐s❡ r❛♥❞♦♠ ✜❡❧❞ ✐s ❛ r❛♥❞♦♠ ❢✉♥❝t✐♦♥ X : R d → R ❣✐✈❡♥ ❜② � ∀ x ∈ R d , X ( x ) = g m i ( x − x i ) , ✇❤❡r❡ i ∈ I { x i } i ∈ I ✐s ❛ P♦✐ss♦♥ ♣♦✐♥t ♣r♦❝❡ss ♦❢ ✐♥t❡♥s✐t② λ > ✵ ✐♥ R d ✱ { m i } i ∈ I ❛r❡ ✐♥❞❡♣❡♥❞❡♥t ✓ ♠❛r❦s ✔ ✇✐t❤ ❞✐str✐❜✉t✐♦♥ F ( dm ) ♦♥ R k ✱ ❛♥❞ ✐♥❞❡♣❡♥❞❡♥t ♦❢ { x i } i ∈ I ✳ ❚❤❡ ❢✉♥❝t✐♦♥s g m ❛r❡ r❡❛❧✲✈❛❧✉❡❞ ❞❡t❡r♠✐♥✐st✐❝ ❢✉♥❝t✐♦♥s✱ ❝❛❧❧❡❞ s♣♦t ❢✉♥❝t✐♦♥s ✱ s✉❝❤ t❤❛t � � R d | g m ( y ) | dy F ( dm ) < + ∞ . R k ❍❡r❡ ✇❡ ❝♦♥s✐❞❡r d = ✷ ❛♥❞✱ ❢♦r s❛❦❡ ♦❢ s✐♠♣❧✐❝✐t②✱ k ≤ ✷ ✇✐t❤ ❛ s✐♥❣❧❡ L ✶ ( R ✷ ) ❢✉♥❝t✐♦♥ g r❛♥❞♦♠❧② ✇❡✐❣❤t❡❞ ❛♥❞ ❞✐❧❛t❡❞ ✿ ( W , R ) ∼ F ✐s ❛ ♣r♦❜❛❜✐❧✐t② ♠❡❛s✉r❡ ♦♥ R × ( ✵ , + ∞ ) ❛♥❞ ❢♦r m = ( w , r ) g m ( x ) = wg ( x / r ) .

❞❡❢❛✉❧t ❊①❛♠♣❧❡ ✶ ✿ ❞✐s❦ ✇✐t❤ r❛♥❞♦♠ r❛❞✐✉s ▲❡t d = ✷✱ T ❛ ❜♦✉♥❞❡❞ ❝❧♦s❡❞ r❡❝t❛♥❣❧❡ ♦❢ R ✷ ❛♥❞ g = ✶ D ✳ ❈♦♥s✐❞❡r r❛♥❞♦♠ ❞✐s❦ ♦❢ r❛❞✐✉s r = r ✶ ♦r r = r ✷ ✇✐t❤ ✵ < r ✶ < r ✷ ✭❡❛❝❤ ✇✐t❤ ♣r♦❜❛❜✐❧✐t② ✶ / ✷✮✱ s❛♠❡ ✇❡✐❣❤ts W = ✶ ❛✳s✳ ❛♥❞ ✐♥t❡♥s✐t② λ > ✵ ❚❤❡ ♥✉♠❜❡r n ♦❢ ❝❡♥t❡rs ✐♥ T ✐s ❛ P♦✐ss♦♥ r❛♥❞♦♠ ✈❛r✐❛❜❧❡ ♦❢ ♣❛r❛♠❡t❡r λ | T | ❚❤❡ ❝❡♥t❡rs x ✶ , . . . , x n ❛r❡ t❤r♦✇♥ ✉♥✐❢♦r♠❧②✱ ✐♥❞❡♣❡♥❞❡♥t❧② ♦♥ T ❚❤❡ r❛❞✐✉s R ✶ , . . . , R n ❛r❡ ❛tt❛❝❤❡❞ t♦ ❡❛❝❤ ❝❡♥t❡r ❜② ✢✐♣♣✐♥❣ ❛ ❝♦✐♥ t♦ ❝❤♦♦s❡ ❜❡t✇❡❡♥ r ✶ ♦r r ✷ ✳

❞❡❢❛✉❧t ❊①❝✉rs✐♦♥ s❡t ❲❡ ❝♦♥s✐❞❡r t❤❡ ❡①❝✉rs✐♦♥ s❡t ♦r t❤❡ ❧❡✈❡❧ s❡t ♦❢ ❧❡✈❡❧ u ∈ R ♦❢ X ✐♥ T ❞❡✜♥❡❞ ❜② E X ( u ) ∩ T := { x ∈ T ; X ( x ) ≥ u } ✇✐t❤ E X ( u ) = { X ≥ u } . ✈✐❡✇ ✸❉ ✈✐❡✇ ✷❉ s♦♠❡ ❧❡✈❡❧ ❧✐♥❡s u = ✵ . ✺ u = ✶ . ✺ u = ✷ . ✺

❞❡❢❛✉❧t ❊①❛♠♣❧❡ ✷ ✿ ●❛✉ss✐❛♥ ❦❡r♥❡❧ ▲❡t ✉s ❝❤♦♦s❡ g ( x ) = e − � x � ✷ ✐♥st❡❛❞ ♦❢ ✶ D ✳ ✷ ✈✐❡✇ ✸❉ ✈✐❡✇ ✷❉ s♦♠❡ ❧❡✈❡❧ ❧✐♥❡s u = ✵ . ✺ u = ✶ u = ✶ . ✺

❞❡❢❛✉❧t ▼❛✐♥ q✉❡st✐♦♥s ❲❤❛t ❝❛♥ ❜❡ s❛✐❞ ❛❜♦✉t ✧♠❡❛♥✧ ❣❡♦♠❡tr② ♦❢ ❡①❝✉rs✐♦♥ s❡ts ❄ ❆r❡❛ ❄ P❡r✐♠❡t❡r ❄ ❊✉❧❡r ❈❤❛r❛❝t❡r✐st✐❝❂ # ❝♦♥♥❡❝t❡❞ ❝♦♠♣♦♥❡♥ts ✕ # ❤♦❧❡s ❄ ❑♥♦✇♥ r❡s✉❧ts ❢♦r ❇♦♦❧❡❛♥ ♠♦❞❡❧ ✿ ▼❡❝❦❡ ✭✷✵✵✶✮✱ ▼❡❝❦❡✱ ❲❛❣♥❡r ✭✶✾✾✶✮ ❙♠♦♦t❤ ●❛✉ss✐❛♥ ❛♥❞ r❡❧❛t❡❞ r❛♥❞♦♠ ✜❡❧❞s ✿ ❆❞❧❡r ✭✷✵✵✵✮✱ ❆❞❧❡r✱ ❚❛②❧♦r ✭✷✵✵✼✮✱ ❆③❛ïs✱ ❲s❝❤❡❜♦r ✭✷✵✵✾✮✱ ✳✳✳ ❍✐❣❤ ❧❡✈❡❧s ❢♦r s♦♠❡ ✐♥✜♥✐t❡❧② ❞✐✈✐s✐❜❧❡ ✜❡❧❞s ✿ ❆❞❧❡r✱ ❙❛♠♦r♦❞♥✐ts❦②✱ ❚❛②❧♦r ✭✷✵✶✵✱✷✵✶✸✮✱✳✳✳ ❚✇♦ ❞✐✛❡r❡♥t ❢r❛♠❡✇♦r❦s ✶ P✐❡❝❡✇✐③❡ ❝♦♥st❛♥t ✜❡❧❞s ✭❡❧❡♠❡♥t❛r②✮ ✷ ❙♠♦♦t❤ ✜❡❧❞s ✿ ❛t ❧❡❛st C ✷

❞❡❢❛✉❧t ❈✉r✈❛t✉r❡ ♠❡❛s✉r❡s ▲❡t E ⊂ R ✷ ❜❡ ❛ ✧♥✐❝❡ s❡t✧✳ ■ts ❝✉r✈❛t✉r❡ ♠❡❛s✉r❡s Φ j ( E , · ) ✱ ❢♦r j = ✵ , ✶ , ✷✱ ❛r❡ ❞❡✜♥❡❞ ❢♦r ❛♥② ❇♦r❡❧ s❡t U ⊂ R ✷ ❜② Φ ✷ ( E , U ) = | E ∩ U | ✱ Φ ✶ ( E , U ) = ✶ ✷ H ✶ ( ∂ E ∩ U ) = ✶ ✷ P❡r ( E , U ) ✶ Φ ✵ ( E , U ) = ✷ π ❚❈ ( ∂ E , U ) ✱ ✇❤❡r❡ H ✶ ( ∂ E ∩ U ) ✐s t❤❡ ❧❡♥❣❤t ❛♥❞ ❚❈ ( ∂ E , U ) t❤❡ t♦t❛❧ ❝✉r✈❛t✉r❡ ♦❢ t❤❡ ♣♦s✐t✐✈❡❧② ♦r✐❡♥t❡❞ ❝✉r✈❡ ∂ E ✐♥ U ✳ ❘❡❢ ✿ ❙❝❤♥❡✐❞❡r✱ ❲❡✐❧✱ ❙t♦❝❤❛st✐❝ ❛♥❞ ■♥t❡❣r❛❧ ●❡♦♠❡tr②

❞❡❢❛✉❧t P✐❡❝❡✇✐s❡ r❡❣✉❧❛r ❝✉r✈❡ ❆ ❏♦r❞❛♥ ❝✉r✈❡ Γ ⊂ R ✷ ✐s ♣✐❡❝❡✇✐s❡ r❡❣✉❧❛r ✐❢ Γ = R Γ ∪ C Γ ✇✐t❤ # C Γ < + ∞ ❢♦r x ∈ R Γ ♦♥❡ ❤❛s x = γ ( s ) ❢♦r s♦♠❡ s ∈ ( ✵ , ε ) ✇✐t❤ γ : ( ✵ , ε ) → Γ C ✷ ✱ ❛r❝ ❧❡♥❣t❤ ♣❛r❛♠❡tr✐③❡❞✳ ❚❤❡♥✱ | γ ( ✵ , ε ) | ✶ = ε ✳ ❚❤❡ s✐❣♥❡❞ ❝✉r✈❛t✉r❡ κ Γ ( x ) ♦❢ Γ ❛t x ✐s κ Γ ( x ) = � γ ′′ ( s ) , γ ′ ( s ) ⊥ � . ❢♦r x ∈ C Γ ♦♥❡ ❤❛s x = γ ( ✵ ) ✇✐t❤ γ : ( − ε, ε ) → Γ ❝♦♥t✐♥✉♦✉s ❛♥❞ C ✷ ♦♥ ( − ε, ε ) � { ✵ } s✳t✳ γ ′ ❛❞♠✐ts ❧✐♠✐ts γ ′ ( ✵ − ) ∈ S ✶ ❛♥❞ γ ′ ( ✵ + ) ∈ S ✶ ❛t ✵✳ ❚❤❡♥✱ | γ ( − ε, ε ) | ✶ = ✷ ε ✳ ❚❤❡ t✉r♥✐♥❣ ❛♥❣❧❡ ❛t ❛ ❝♦r♥❡r ♣♦✐♥t x = γ ( ✵ ) ∈ C Γ ✐s t❤❡ ❛♥❣❧❡ α Γ ( x ) ∈ ( − π, π ) ❜❡t✇❡❡♥ t❤❡ t❛♥❣❡♥t ✏❜❡❢♦r❡✑ ❛♥❞ t❤❡ ♦♥❡ ✏❛❢t❡r✑ x α Γ ( x ) = ❆r❣ γ ′ ( ✵ + ) − ❆r❣ γ ′ ( ✵ − ) ∈ ( − π, π ) .

❞❡❢❛✉❧t ❚♦t❛❧ ❝✉r✈❛t✉r❡ ❛♥❞ ❊✉❧❡r ❝❤❛r❛❝t❡r✐st✐❝ ❚❤❡ t♦t❛❧ ❝✉r✈❛t✉r❡ ♦❢ Γ ✐♥ U ✐s ❞❡✜♥❡❞ ❛s � � κ Γ ( x ) H ✶ ( dx ) + ❚❈ (Γ , U ) := α Γ ( x ) . R Γ ∩ U x ∈C Γ ∩ U o ●❛✉ss✲❇♦♥♥❡t ❚❤❡♦r❡♠ ✿ ▲❡t E ⊂ U ❜❡ ❛ r❡❣✉❧❛r r❡❣✐♦♥ ✐❡ E = E s✉❝❤ t❤❛t ∂ E ✐s ❢♦r♠❡❞ ❜② n ♣✐❡❝❡✇✐s❡ r❡❣✉❧❛r ♣♦s✐t✐✈❡❧② ♦r✐❡♥t❡❞ ❞✐s❥♦✐♥t ❏♦r❞❛♥ ❝✉r✈❡s Γ ✶ , . . . , Γ n t❤❡♥ � n ❚❈ ( ∂ E , U ) := ❚❈ (Γ i , U ) = ✷ πχ ( E ) , i = ✶ ✇❤❡r❡ χ ( E ) ✐s t❤❡ ❊✉❧❡r ❝❤❛r❛❝t❡r✐st✐❝ ♦❢ E ✱ χ ( E ) = # ❝♦♥♥❡❝t❡❞ ❝♦♠♣♦♥❡♥ts − # ❤♦❧❡s . ■t ❢♦❧❧♦✇s t❤❛t Φ ✵ ( E , U ) = χ ( E ) ✳