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F Archimedes G F P G F- , P = MU P Levi (M Levi ) G :=G(F), P := P(F), M := M(F), U := U(F)... IG P(σ) M σ G . (Langlands) . . . .. . . . G π , M σ ,π IG P(σ) (Langlands ) . ( ) 2 / 27(1)
rP Jacquet IG P , G π M σ HomM(rP(π), σ) ! HomG(π, IGP(σ)). Langlands , . ⇒ ( ) . ( ) 3 / 27(2)
Irr(G) G Irru(G) G Π0(G) G Π2(G) G Πtemp(G) GΠ0(G)⊂Π2(G)⊂ Πtemp(G)⊂ Irru(G)⊂ Irr(G)
. Plancherel µ(σ) IG P(σ) , . Harish-Chandra R- EndG(IGP(σ)) . R- IGP(σ) . ( ) 5 / 27
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X(M) M F -aM := Hom(X(M), R),a∗M = X(M) ⊗ R HM : M→ aM . exp'χ, HM(m)( = |χ(m)|F (χ ∈ X(M)) M1 := Ker H M λ∈ a∗ M,C := a ∗ M⊗ C e λ∈ ˆA M:= Hom(M/M1, C×) eλ : M/M1 + m ,→ exp'λ, H M(m)( ∈ C× . ( ) 6 / 27(2)
M (σ, V) , IG P(V) I G P(σ) (σλ, Vλ) := (σ⊗ eλ, V) (λ∈ a∗ M,C) , IG P(Vλ) I G P(σλ) P, P- ∈ P(M) M F -, P- :=P-(F), P- = M-U -. ( ) . . . .. . . . JP-|P(σλ)φ(g) := ! U∩U-\U-φ(u -g)du-(g ∈ G, φ ∈ IG P(Vλ)) AM M , ΣM G AM , ΣM ⊃ ΣP P K G ( ) 7 / 27(3)
. (Waldspurger03, Konno03 ) . . . .. . . . (1)φ∈ IG P(Vλ) v∨ ∈ V∨ , α∨(Re(λ)) >> 0, ∀α ∈ ΣP\ ΣP -'JP-|P(σλ)φ( g), v∨( := ! U∩U-\U-'φ(u -g), v∨(du -,JP-|P(σλ)φ( g)∈ (V∨)∨=V. (2) ˆ AM + λ ,→ JP-|P(σλ)φ|K ˆ AM indKK∩P(V)- . (3) IG P(Vλ) + φ ,→ JP-|P(σλ) ∈ I G P-(Vλ)φ HomG(IGP(σλ), IGP-(σλ)) . ( ) 8 / 27(4)
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(Waldspurger03, Konno03, Arthur89 ) . . . .. . . . (1) λ∈ ˆAM φ∈ IGP(Vλ) , JP-|P(σλ)φ . (2) ( )φ∈ IG P(V), φ ∨∈ IG P-(V∨) 'JP-|P(σ)φ, φ∨( = 'φ, JP|P-(σ∨)φ∨(. (3)P, P- ∈ P(M) Weyl a+ P, a + P- ⊂ aM ,d(P, P-) a+ P, a + P- . P1, P2, P3 ∈ P(M) d(P3,P1) = d(P3,P2) + d(P2,P1) , . JP3|P1(σλ) = JP3|P2(σλ)◦ JP2|P1(σλ) ( ) 9 / 27
Plancherel
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σ M(F) ˆ AM := Hom(M/M1, C×). . . (Waldspurger03, Sauvageot97) . . . .. . . . ˆ AM Zariski ΞP(σ) , eλ ∈ ΞP(σ) IG P(σλ) . P P opposite . Schur eλ∈ ΞP(σ) j(σλ) := J P|P(σλ)JP| P(σλ)∈ EndG(IGP(σλ))! C ˆ AM . ( ) 10 / 27Plancherel
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Σred P ΣP α∈ Σred P Mα ⊃ M Levi Mα , ΣP∩Mα = {α} . γ(G/M) γ(G/M) := ! UδP (mP( u))d u . δP P mP( u) u∈ U ( P = M U) G P M . . (Plancherel ) . . . .. . . . σ M .λ∈ a∗ M,C . µ(σλ) := j(σλ)−1 " α∈Σred P γ(Mα/M)2 ( ) 11 / 27Plancherel
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Placnerel Waldspurger . Plancherel
ˆ A1 M . G Plancherel . Plancherel Harish-Chandra . Harish-Chandra Eisenstein c , Plancherel . µ(σλ) M P . µ(σλ) Weyl W . µ(wσλ) = µ(σλ), ∀w ∈ W. ( ) 12 / 27
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R -. (Harish-Chandra, Waldspurger) . . . .. . . . π∈ Πtemp(G) ,G Levi M σ∈ Π2(M) (M, σ) G P ∈ P(M) π IGP(σ) . ⇒ Πtemp(G) IGP(σ) (σ∈ Π2(M)) . ( ) 13 / 27R
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. ( , Arthur89) . . . .. . . . Levi M σ ∈ Π2(M) AMˆ {rP-|P(σλ)}P, P-∈P(M) ⊂ C( ˆAM) . (1) RP-|P(σλ) := rP-|P(σλ)−1JP-|P(σλ) λ∈ ˆAM , . RP3|P1(σλ) = RP3|P2(σλ)◦ RP2|P1(σλ) (P1, P2, P3 ∈ P(M)) (2) ( )φ∈ IG P(V), φ∨∈ I G P-(V∨) . 'RP-|P(σλ), φ∨( = 'φ, RP|P-(σ∨ λ)φ ∨( (3)RP-|P(σλ) Re(λ)∈ a+ P(Weyl ) . (4)RP-|P(σλ) λ∈ ˆA1 M :={χ ∈ ˆAM | χ } . ( ) 14 / 27R
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(σ, V) M(F) W(M) := NG(M)/M, W(M)σ:={w ∈ W(M) | wσ! σ} w∈ W(M)σ M+w :='M, w( σ+ w ind M+ w M σ (σ M + w ) δ+ P,w P δP M + w A(σ+ w) : IGw−1P(V)+ φ ,→ δ + P,w(w)σ + w(w)φ(w−1∗) ∈ IGP(V) . w∈ W(M)σ . RP|P(w, σ) : IGP(σ)→ IGP(σ) . RP|P(w, σ) : IGP(V) Rw−1 P|P(σ) −→ IG w−1P(V) A(σ+ w) −→ IG P(V) ( ) 15 / 27R
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. . . . .. . . . W(M)0 σ:={w ∈ W(M)σ | RP|P(w, σ) } . W(M)0 σ W(M)σ W(M)σ) W(M)0σ. . (R- ) . . . .. . . . Rσ:= W(M)σ/W(M)0σ . (Harish-Chandra, ) . . . .. . . . EndG(IGP(σ)) {RP|P(w, σ)| w ∈ W(M)σ} . . (Silberger78) . . . .. . . . {RP|P(w, σ)| w ∈ Rσ} EndG(IGP(σ)) . dim EndG(IGP(σ)) = *Rσ. ( ) 16 / 27R
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Rσ+ w1, w2 , ζσ∈ C2(Rσ, C×) RP|P(w1w2, σ) = ζσ(w1, w2)RP|P(w1, σ)RP|P(w2, σ) . [ζσ] ∈ H2(Rσ, C×) ([Chao-Li]). [ζσ] Zσ⊂ H2(Rσ, C×) , 1→ Zσ → ˜Rσ → Rσ→ 1 . H2(Rσ, C×) → H2( ˜Rσ, C×) ζσ λσ ∈ C1( ˜Rσ, C×) ζσ(w1, w2) = λσ( ˜w1)λσ( ˜w2) λσ( ˜w1w2˜ ) ( ˜Rσ+ ˜wi ,→ wi ∈ Rσ, i = 1, 2). ( ) 17 / 27R
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˜Rσ + ˜r ,→ ˜R(˜r, σ) := λσ(˜r)−1R(r, σ)∈ AutG(IGP(σ)). χσ := λσ|Zσ Zσ . Π( ˜Rσ, χσ) :={ρ ∈ Irr( ˜Rσ) | ρ|Zσ =χσ} . (Arthur93) . . . .. . . . (1) ˜Rσ× G . IGP(σ) ! # ρ∈Π( ˜Rσ,χσ) ρ∨⊗ πρ (2)JH(IGP(σ)) IGP(σ) . Π( ˜Rσ, χσ) ! JH(IGP(σ)) ( ) 18 / 27(1)
P0 G ,P0 ⊃ M0 G Levi , Σ0 := ΣM0 Σ0 ⊃ ∆P0 ∆P:={α0|aM | α0 ∈ ∆P0 \ ∆P0∩M} a∗,+ P :={λ ∈ a ∗ M | α ∨(λ) > 0∀α ∈ ∆ P} W M0 G Weyl . (Langlands ) . . . .. . . . (1)(σ, V) ∈ Πtemp(M), P ∈ P(M), λ ∈ a∗,+P , . JGP(σλ) := Im[J P|P(σλ) : IGP(σ)→ IG P(σ)](Langlands ) (2) π ∈ Irr(G) ,π ! JG P(σλ) (P, σ, λ) W- , . ( ) 19 / 27(2)
. ( , Bernstein-Zelevinski77 ) . . . .. . . . π∈ Irr(G) , Levi Mc ρ ∈ Π0(Mc) G . [Mc, ρ] π . (i)∃Pc ∈ P(Mc), π -→ IGP c(ρ). (ii)∀Pc ∈ P(Mc), IGP c(ρ) π . . (Langlands-Casselman , Konno03 ) . . . .. . . . π ∈ Irr(G) ,[Mc, ρ] . (i)π ⇔ Re(Exp(rPc(π)))⊂ +a∗ Pc, ∀Pc ∈ P(Mc). (ii)π ⇔ Re(Exp(rPc(π)))⊂+a∗P c, ∀Pc ∈ P(Mc). ( ) 20 / 27(3)
. (Harish-Chandra, Silberger79 ) . . . .. . . . P = MU , IG P(σ) (σ∈ Π2(M)) W(M)σ! {1}, µ(σ) ! 0. ⇒ . (Harish-Chandra, Silberger79 ) . . . .. . . . P = MU ,σ ∈ Π2(M) . IG P(σλ0) (λ0 ∈ a∗M\ a∗G) µ(σλ) λ = λ0 . ⇒ (Langlands ) ( ) 21 / 27G = U(2), U(3)
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E/F F F U(2), U(3) . U(2)(F) := $ g∈ GL2(E) %% %% %% t g & 0 1 −1 0 ' g = & 0 1 −1 0 '( U(3)(F) := g ∈ GL3(E) %% %% %% %% % t g 0 0 1 0 −1 0 1 0 0 g = 0 0 1 0 −1 0 1 0 0 B = MU(Borel ) M = {diag(a, a−1) | a ∈ E×} (G = U(2)) {diag(a, t, a−1) | a ∈ E×, t ∈ E1} (G = U(3)). E1 =U(1)(F). ( ) 22 / 27G = U(2), U(3)
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σ∈ Irru(M) = Π2(M) χ∈ Irru(E×), η∈ Irru(E×/F×)
σ(diag(a, a−1)) = χ(a) (G = U(2))
σ(diag(a, t, a−1)) = χ(a)ηu(t) (G = U(3))
. ηu : E1 + z/ z ,→ η(z) ∈ C1. λ∈ C
σλ(diag(a, a−1)) = χ(a)|a| λ
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E (G = U(2))
σλ(diag(a, t, a−1) = χ(a)|a| λ
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Eηu(t) (G = U(3))
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Irru(E×, δ) :={χ ∈ Irru(E×)| χ|F× = δ} (δ = 1F×, ωE/F)
*Rσ≤ *W(M) = 2 , ⇒Harish-Chandra Langlands ( ) 23 / 27
G = U(2), U(3)
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. (Plancherel , Keys-Shahidi88 ) . . . .. . . . (1)G = U(2) µ(σλ) = e1(λ) LF(1− λ, (χ|F×)−1)LF(1 + λ, χ|F×) LF(λ, χ|F×)LF(−λ, (χ|F×)−1) .(2)G = U(3) ,ωE/F E/F
µ(σλ) =e2(λ) LE(1− λ, χ−1η)LF(1− 2λ, ωE/F(χ|F×)−1) LE(λ, χη−1)LF(2λ, ωE/Fχ|F×) × LE(1− λ, χη −1)LF(1 + 2λ, ωE/Fχ|F×) LE(−λ, χ−1η)LF(−2λ, ωE/F(χ|F×)−1) . e1(λ), e2(λ) µ(σλ) . ( ) 24 / 27