Sp (1)-

SOFIANE BOUARROUDJ AND GUOWU MENG

ABSTRACT. 𝔰𝔬(4n) Sp(1)-. Laplace-Runge-Lenz Sp(1)- . A. Weinstein. 𝔰𝔬(4n) TnSp(1). ( n := n∖{0} Sp(1) Tn Sp (1) n.)

. Laplace-Runge-Lenz Weinstein.

Date: May 1, 2026.

The authors were supported by the Hong Hong Research Grants Council under RGC Project No. 16304014; SB was also supported by the grant NYUAD-065.

1.

. SO(4) SO(3). 𝔰𝔬(4,2) . I. A. Malkin V. I. Manko [1] 1966. ( 2 [2].) 𝔰𝔬(4,2) .

MICZ-. A. Barut G. Bornzin [3] . MICZ- MICZ- [4] [5] [6].

[78] . [9]: Laplace-Runge-Lenz .

[10] U(1)- ( [11]). . Sp(1)- [12] U(1)-. Laplace-Runge-Lenz Sp(1)- Laplace-Runge-Lenz.

ℍ                thesetofquaternions
Hn(ℍ)            theJordanalgebraofquaternionichermitian matricesofordern
Im ℍ              thesetofimaginaryquaternions
i,j,k              thestandardorthonormalbasis forIm ℍ such thatij = k
¯q                thequaternionicconjugateofquaternionq,e.g., ¯k = − k
Req              1(q+ ¯q)
Im q              21(q− ¯q)
⌟                2theinteriorproductofvectorswith forms
∧                thewedge productofforms
d                theexteriorderivative operator
πX : T∗X → X     thecotangentbundleprojection
G                acompactconnectedLiegroup
𝔤,𝔤∗              theLiealgebraof G and itsdual
ξ                an elementin𝔤
⟨, ⟩             eithertheparing ofvectors withco-vectorsorinnerproduct
⟨|⟩              theinnerproductontheJordan algebraHn(ℍ )
Ada              theadjointactionofa ∈ G on𝔤
P → X            aprincipalG -bundle
Θ                a𝔤-valueddifferentialone- formon P that
                 definesa principalconnection onP →  X
Ra               therightaction onP bya ∈ G
Xξ               thevector fieldon P whichrepresentsthe
                 infinitesimal rightaction onP by ξ ∈ 𝔤
F                ahamiltonianG -space
ℱ := P ×G F       thequotientofP × F bytheactionofG
Φ : F → 𝔤∗       theG -equivariantmoment map
ℱ♯               Sternbergphasespace
𝒲                Weinstein’suniversalphasespace

2.

Sp(1)- n μ 𝔰𝔬(4n) . 𝔰𝔬(4n) Hn() n [13]. ( [14] ).

u V := Hn() Lu u u,v V Suv = [Lu,Lv] + Luv [Lu,Lv] : LuLv LvLu uv Luv Lu(v) u v. {uvw} Suv(w).

[Suv,Szw ] = S{uvz}w − Sz{vuw} forany u,v,z,w inV .

Suv . 𝔰𝔱𝔯 V . 𝔰𝔱𝔯 = 𝔰𝔲(2n) ℝ ℝ Lee.

𝔠𝔬 𝔰𝔱𝔯.

𝔠𝔬 = V ⊕ 𝔰𝔱𝔯⊕ V∗.

z V Xz :

[Suv,Xz] = X {uvz}

V . V V w W Y w

[Suv,Yw] = − Y{vuw}.
[Xu,Yv] = 0, [Yu,Yv] = 0, [Xu,Yv] = − 2Suv forany u,v inV .

𝔠𝔬 = 𝔰𝔬(4n) .

3.

Sternberg [15] U(1)- [10].

A. Weinstein Sternberg. Sternberg . . A. Weinstein [16] Weinstein.

3.1. S. Sternberg A. Weinstein. S. Sternberg [15] A. Weinstein [16]. Sternberg:

(i)

G G- P X Θ

(ii)

G F Ω G- Φ: F 𝔤. 𝔤 G.

- G Kirillov-Kostant-Souriau G.

Θ G- P X 𝔤 P :

1) Ra1Θ = AdaΘ a G 2) Θ(Xξ) = ξ ξ 𝔤.

a G Ra1 a1 P Ada a 𝔤 Xξ P ξ 𝔤 P f C(P)

                        ||     ||
(3.1)               ℒX ξf ||p =-d||   f(p⋅exp(tξ)).
                            dt t=0

[Xξ,Xη] = X[ξ,η] [Xξ,Xη] = X[ξ,η].

() G P G TP G- ρ: TP 𝔤. πP TP P ρ

⟨ρ(z),ξ⟩ = ⟨z,Xξ(πP(z))⟩.

: p P

                            𝔤  →   TpP
(3.2)                        ξ  ↦→   X ξ(p)

TpP 𝔤. ρ: TP 𝔤.

G- ρ (Rg)(Xξ) = XAd g1(ξ) Adg(α) = αAdg1 α 𝔤. ρ dρ,ξ= ˆXξ ωP. ωP TP ˆXξ TP Xξ.

                                                             ∂Xi
z = pi(z)dxi|πP(z), ωP = dpi ∧dxi, X ξ = Xiξ ∂-i, Xˆξ = Xiξ-∂i − pi-ξj-∂
                                         ∂x           ∂x     ∂x  ∂pj

ρ,ξ= piXξi. xi P .

ρ Φ G-

ψ :  T∗P × F → 𝔤∗.

(x,y) ρ(x) + Φ(y).

P X G- ρ|TpP: TpP 𝔤 p P ρ: TP 𝔤 . ψ . ψ1(0) TP ×F . 0 𝔤 G ψ1(0) 1 [17] ω ψ1(0)∕G πω = ι(ωP + Ω) ωP P π ι :

     ψ− 1(0)      T∗P × F


πι    ψ− 1(0)∕G

(ψ1(0)∕G,ω) Weinstein 𝒲. .

“” Θ P X . p P x p X ( Θ) TxX TpP .

   T∗P     T∗X


ππPX P       X

X P . P˜

          ∗
        T  X

π P     X
 X

G- TP ˜P F G-

     ∗         ˜
αΘ : T P × F → P × F.

Weinstein αΘ ψ1(0) G

--
αΘ :  ψ−1(0)∕G → P˜×G F.

ωΘ := ˜P×GF αΘ(ωΘ) = ω. (Θ) Sternberg Θ [15]. Sternberg Weinstein 𝒲.

3.2. Sternberg Sp(1)-. Sp(1)- ( ) ( ) n 2 ( ) μ 0. n μ Sternberg μ [12]:

(i)

G Sp(1) ( SU(2)) G-

                             n
                           ℍ ∗  →   𝒞1  †
(3.3)                         Z  ↦→   nZZ
                                 ¯
(3.4)                     Θ = Im(Z-⋅d2Z-).
                                |Z|

𝒞1 Hn() n. Hn() 𝒞1 Hn(). 𝒞1 Hn() 𝒞1 [12] .

(ii)

𝔤 𝔤 := Im ,i j k 𝔤. G

                                     ¯   2
(3.5)                 F := {ξ ∈ Imℍ | ξξ = μ }

Ωμ Kirillov-Kostant-Souriau

                              ⟨ξ,dξ ∧dξ⟩
(3.6)                    Ω μ = --2|ξ|2---.

ξ = ξ1i + ξ2j + ξ3k F :

               1  2    3    2  3    1     3 1     2
(3.7)         {ξ ,ξ } = ξ , {ξ ,ξ } = ξ , {ξ ,ξ } = ξ .

(: ij = k.)

(iii)

G-

                           Φ : F →   Im ℍ
(3.8)                           ξ ↦→   2ξ

( G F Im .) Φ G 2 (3.8)

d⟨Φ,η⟩ = X η ⌟ Ωμ.

Xη F F η Xη(ξ) = (ξ,[η,ξ]) TξF .

3.3. Weinstein Sp(1)-. Sp(1) n (Z,q) n × Sp(1) Z [q] Z 1 × 1- [q]. Sp (1) Tn . Tn Tn Z W . n:

⟨U,V ⟩ = Re(U†V),

Tn Tn Tn : U,V n

{⟨U,Z ⟩,⟨V,W ⟩} = ⟨U,V ⟩, {⟨U,Z ⟩,⟨V,Z⟩} = {⟨U,W ⟩,⟨V,W ⟩} = 0.

Tn Tn 𝔤 𝔤 ρ Tn 𝔤 (Z,W) Im(WZ). ψ: Tn × F 𝔤

                                    †
(3.9)                ψ (Z, W,ξ) = Im(W Z) + 2ξ.

g (Z,W,ξ) (Z g1,W g1,gξg1).

ψ ψ˜ : Tn ×𝔤 𝔤 : ˜ψ(Z,W, ξ) = Im (W †Z )+ 2ξ. ˜ψ 1(0) ξ = 1
2Im(WZ). G-. .

      †       †
{⟨i,W  Z ⟩,⟨j,W Z ⟩} =   {⟨W i,Z⟩,⟨W j,Z ⟩}
                   =   {⟨W i,Z⟩,⟨W j,Z ⟩}− < i ↔ j >
                   =   − {⟨W i,Z ⟩,⟨W, Zj⟩}− < i ↔ j >
                   =   − ⟨W i,Zj⟩†− < i ↔ j >
                   =   − 2⟨k,W Z⟩.

ξ1 = 1
2i,WZξ2 = 1
2j,WZξ3 = 1
2k,WZ⟩ {ξ12} = ξ3 (3.7) .

Sp(1)- Tn ×𝔤 Tn ψ˜ 1(0) Sp(1)- ψ˜ 1(0) Tn. ψ1(0) Sp(1)- ψ˜ 1(0)

                    {                                    }
       −1                                1     †
𝒲 μ := ψ (0)∕Sp(1) = Sp(1)⋅(Z,W, ξ) | ξ = − 2Im(W Z),|ξ| = μ

TnSp(1). 𝒲μ

{Sp(1) ⋅(Z,W  ) | |Im(W †Z)| = 2μ}

TnSp(1). Sternberg μ Weinstein 𝒲μ Sternberg TnSp(1).

(ii) 1 Hn() TnSp(1) 𝒲μ Sternberg μ.

4.

Sp(1)- n μ. Sternberg μ T𝒞1. V := Hn() T𝒞1 T𝒞1 μ T𝒞1 . x π ( V )

        T𝒞
          1

        TV


ιxπτtVV            V

ι τV t V . x π μ T𝒞1 x π. Hn() ⟨∣⟩ u Hn() xu⟩ ℱμ.

1. Hn() Sternberg μ Y u 𝒴u := xuXe 𝒳e := xπ2+ -μ2--
⟨e|x⟩. (eα) Hn() u Lu :

                      ∑
(4.1)                2-   ℒ2eα = ℒ2e + 𝒳e𝒴e − μ2.
                    n  α

( ) Xe Y u .

. Sternberg Weinstein

            --           −1            ♯    ˜
(4.2)        αΘ :  𝒲μ := ψ  (0)∕Sp(1) → ℱμ := P ×Sp(1) F,

Weinstein 𝒲μ .

1.

(i).

Sp(1) (Z,W,ξ) 𝒲μ 𝒴u 𝒳e 1.

𝒴  ∘α- (Sp(1)⋅(Z,W, ξ)) = ⟨Z, uZ⟩,  𝒳 ∘ α-(Sp(1)⋅(Z, W,ξ)) = 1 |W |2.
 u   Θ                            e   Θ                 4
(ii).

u v V := Hn() Sp(1)-

                    (           1
                    ||{  𝒳u   :=   4⟨W,uW ⟩
(4.3)                    𝒴v  :=   ⟨Z, vZ⟩
                    ||(           1
                      𝒮uv   :=   2⟨W,(u⋅v)Z ⟩

Tn. u v u v. u v z w V :

(
||{𝒳u, 𝒳v } = 0, {𝒴u,𝒴v} = 0,  {𝒳u, 𝒴v} = − 2𝒮uv,
||{
     {𝒮uv, 𝒳z} = 𝒳 {uvz},  {𝒮uv,𝒴z} = − 𝒴{vuz},
||||
(        {𝒮uv, 𝒮zw} = 𝒮{uvz}w − 𝒮z{vuw}.

TnSp(1) Hn().

(iii).

e V (eα) V u = 𝒮 eu u V .

                     ∑
(4.4)               -2   ℒ 2eα = ℒ 2e + 𝒳e 𝒴e − μ2.
                   n  α

Proof.

(i).

αΘ Θ. Z n x = nZZ. (x,ẋ) 𝒞1 x (Z,Ż) Z n. (3.4)

     †     †           †
n(Z˙Z  + ZZ˙ ) = ˙x, Im (Z ˙Z) = 0.
      1       trx˙
˙Z = n|Z|2(x˙Z − -2- Z).

Θ- Tn T𝒞1 (Z,W, ) (x,π∣⟩) x = nZZ

                           1   ⟨        tr ˙x ⟩
(4.5)              ⟨π | ˙x⟩ = n|Z-|2 W, ˙xZ − -2-Z  .

(x,ux) Tx𝒞1

              1  ⟨           tr(ux) ⟩
⟨π | ux⟩ =  n-|Z-|2  W,(ux)Z − --2---Z    ux istheJordan productofu withx
              1  ⟨       †      †              † ⟩
         =  2|Z|2 W, uZZ  Z + ZZ uZ − Retr(uZZ )Z
            1
(4.6)     =  2 ⟨W, uZ⟩.
                --
(4.7)            αΘ(G ⋅(Z,W, ξ)) = G⋅(Z,nZZ †,π,ξ).
    --                           †             †
𝒴u ∘ αΘ(G ⋅(Z, W,ξ)) = ⟨x | u⟩ = ⟨nZZ | u⟩ = Re tr (ZZ u) = ⟨Z,uZ ⟩
    --                           μ2              nμ2
𝒳e ∘αΘ(G ⋅(Z,W,ξ))  =  ⟨x | π2⟩+ ⟨e | x⟩-= ⟨π | πx⟩ + trx
                       1          μ2
                    =  - ⟨W, πZ ⟩+ --2- using Eq.(4.6)
                       2          |Z |   2
                    =  n-⟨π | (ZW †)+⟩+ μ-2.
                        2              |Z |

(ZW)+ = 1
2(ZW + WZ). (x,(ZW) +) 𝒞1 x. (4.5)

                             ⟨                        ⟩
𝒳  ∘α- (G ⋅(Z,W, ξ)) =   -1--- W, (ZW  †) Z − tr-(ZW--†)+-Z  + -μ2-
  e  Θ                  2|Z |2 ⟨        +         2  ⟩      |Z|2
                        -1---        †      ⟨W,-Z⟩-     -μ2-
                    =   2|Z |2  W, (ZW   )+Z  −   2  Z   + |Z |2
                        -1---⟨      †    ⟩  --1--     2   μ2--
                    =   2|Z |2  W,(ZW  )+Z  − 4|Z|2⟨W, Z⟩ +  |Z|2
                         1   (   2  2       †  2        2)   μ2
                    =   4|Z-|2- |W ||Z| + Re(W  Z) − ⟨W, Z⟩  + |Z|2
                         1   (                   )   μ2
                    =   4|Z-|2- |W |2|Z|2 + (Im(W †Z))2 + |Z-|2-
                         1   (                   )   μ2
                    =   ---2- |W |2|Z|2 − |Im (W †Z )|2 +---2
                        41|Z |                        |Z|
                    =   4|W |2.
(ii).

{𝒳 u, 𝒳 v} = 0 {𝒴 u, 𝒴 v} = 0.

             1
{𝒳u,𝒴v}  =   4 {⟨W, uW ⟩,⟨Z,vZ ⟩}
         =   {⟨W, uW ⟩,⟨Z, vZ⟩} = − ⟨uW,vZ ⟩
         =   − 2𝒮uv
{𝒮uv,𝒮zw }  =  1 {⟨W, (u⋅v)Z⟩,⟨W,(z ⋅w )Z⟩}
               41
            =  4 {⟨W, (u⋅v)Z⟩,⟨W,(z ⋅w )Z⟩}− < (u⋅v) ↔ (z ⋅w) >
                 1      †            1      †
            =  − 4⟨(z ⋅w) W,(u ⋅v)Z ⟩+ 4⟨(u⋅v) W,(z ⋅w )Z ⟩
            =  1⟨W, [u ⋅v,z ⋅w]Z⟩
               4
            =  𝒮 {uvz}w − 𝒮z {vuw}

{uvz} = 1
2(u v z + z v u) {vuw} = 1
2(v u w + w u v).

              1                        1
{𝒮uv,𝒳z } =   8 {⟨W, (u⋅v)Z⟩,⟨W,zW ⟩} = 4 {⟨W,(u ⋅v)Z ⟩,⟨W, zW ⟩}
              1                1
          =   4⟨W, (u ⋅v⋅z)W ⟩ = 4 ⟨W, (z ⋅v⋅u)W ⟩
          =   1⟨W, (z ⋅v⋅u +u ⋅v⋅z)W ⟩
              8
          =   𝒳 {uvz}.
              1
{𝒮uv,𝒴z}  =   -{⟨W,(u ⋅v)Z ⟩,⟨Z,zZ ⟩} = {⟨W,(u ⋅v)Z ⟩,⟨Z,zZ ⟩}
          =  −2⟨Z,(z ⋅u⋅v)Z ⟩ = − ⟨Z,(v⋅u ⋅z)Z⟩
               1
          =  − 2⟨Z,(z ⋅u ⋅v+ v ⋅u⋅z)Z⟩
          =  − 𝒴{vuz}.

𝒮 uv 𝒳 z 𝒴 w Tn ( Tn) Sp(1) Sp(1) Tn TnSp(1) Hn().

(iii).

u = 1
2W,uZ

2∑  ℒ 2   =  -1-∑  ⟨W, eαZ⟩2 = n∑  ⟨(ZW †)+ | eα ⟩2
n α   eα     2n  α            2 α
             n-     †       †      1  (    †  )2
          =  2 ⟨(ZW  )+ | (ZW )+⟩ = 2tr  (ZW   )+
          =  1tr (ZW  † + W Z †)2
             8
          =  1tr(Z(W †ZW †)+ (W Z †W )Z † + |W |2ZZ † + |Z |2W W †)
             81    †  2    †   2   1   2   2
          =  8((W  Z) + (Z W ) )+ 4|W ||Z|
             -1   †     †   2  -1   †     †   2  1   2   2
          =  16(W  Z − Z W ) + 16(W  Z + Z W ) + 4|W ||Z|
          =  − 1|Im(W †Z )|2 + 1⟨W, Z⟩2 + 1|W |2|Z|2
               42    2      4         4
          =  − μ + ℒe + 𝒳e 𝒴e.

1. . (ii) 𝔰𝔬(4n) TnSp(1) . Sternberg TnSp(1) (i) 1. 1 (iii) .

4.1. 1 Sp(1)- n μ.

4.2. Sternberg TnSp(1) Sternberg TnSp(1). Sp(1) Tn Sp(1) n 6 [12].

4.3. [9] 1 Sp(1)- T𝒞1

H  = 1𝒳e-− -1-
     2𝒴e   𝒴e

Laplace-Runge-Lenz

       (          )
𝒜  = 1  𝒳  − 𝒴 𝒳e- +  𝒴u-
 u   2   u    u𝒴e     𝒴e

𝒳u 𝒴u Xu Y u 1.

    1⟨x|π2⟩  -μ2   1
H = 2   r  + 2r2 − r,

1.1 [12]. r = trx-
n.

5.

1 Suv Xz Y w

𝒮u,v, 𝒳z,  𝒴w

. u 𝒮ue u,v 1
2(𝒮uv + 𝒮vu).

1: Laplace-Runge-Lenz. [10].

1. eα Hn(). α β. 1 :

(i)

𝒳eαeα = n𝒳ee 𝒴eαeα = n𝒴ee

(ii)

4 neα,ueα = −𝒳u𝒴e + 𝒳e𝒴u

(iii)

𝒳eα2 = n𝒳e2 𝒴eα2 = n𝒴e2

(iv)

2 neα,u𝒳eα = −𝒳ue + u𝒳e 2 neα,u𝒴eα = 𝒴ue −ℒu𝒴e

(v)

𝒳eα𝒴eα = n(e2 + μ2),

(vi)

4-
n3eα,eβ2 = 𝒳e𝒴e −ℒe2 + n−2
 nμ2.

2. eα Hn() L2 = 1 2 α,βeα,eβ2 A2 = 1 + α𝒜eα2. H

                 ( 2   n2(n − 1) 2)   (n )2         2
(5.1)        − 2H  L  − ---4----μ   =  2-  (n− 1− A  ).

References

[1]    I. A. Malkin and V. I. Man’ko, Symmetry of the Hydrogen Atom, JETP Letters 2 (1966), 146-148.

[2]    A. O. Barut and H. Kleinert, Transition Probabilities of the H-Atom from Noncompact Dynamical Groups, Phys. Rev. 156 (1967), 1541-1545.

[3]    A. O. Barut and G. Bornzin, SO(4, 2)-Formulation of the Symmetry Breaking in Relativistic Kepler Problems with or without Magnetic Charges, J. Math. Phys. 12 (1971), 841-843.

[4]    G. W. Meng, MICZ-Kepler problems in all dimensions, J. Math. Phys. 48, 032105 (2007).

[5]    G. W. Meng and R. B. Zhang, Generalized MICZ-Kepler Problems and Unitary Highest Weight Modules, J. Math. Phys. 52, 042106 (2011).

[6]    G. W. Meng, The Poisson Realization of so(2, 2k+2) on Magnetic Leaves and and generalized MICZ-Kepler problems, J. Math. Phys. 54 (2013), 052902.

[7]    G. W. Meng, Euclidean Jordan Algebras, Hidden Actions, and J-Kepler Problems, J. Math. Phys. 52, 112104 (2011)

[8]    G. W. Meng, Generalized Kepler Problems I: Without Magnetic Charge, J. Math. Phys. 54, 012109(2013).

[9]    G. W. Meng, The Universal Kepler Problems, J. Geom. Symm. Phys. 36 (2014) 47-57

[10]    S. Bouarroudj and G. W. Meng, The classical dynamic symmetry for the U(1)-Kepler problems, arXiv:1509.08263

[11]    G. W. Meng, On the trajectories of U(1)-Kepler Problems, In: Geometry, Integrability and Quantization, I. Mladenov, A. Ludu and A. Yoshioka (Eds), Avangard Prima, Sofia 2015, pp 219 - 230

[12]    G. W. Meng, On the trajectories of Sp(1)-Kepler Problems, Journal of Geometry and Physics 96 (2015), 123-132.

[13]    P. Jordan, Über die Multiplikation quantenmechanischer Größen, Z. Phys. 80 (1933), 285-291.

[14]    J. Faraut and A. Korányi, Analysis on Symmetric Cones, Oxford Mathematical Monographs, 1994.

[15]    S. Sternberg, Minimal coupling and the symplectic mechanics of a classical particle in the presence of a Yang-Mills field. Proc Nat. Acad. Sci. 74 (1977), 5253-5254.

[16]    A. Weinstein, A universal phase space for particles in Yang-Mills fields. Lett. Math. Phys. 2 (1978), 417-420.

[17]    J. Marsden and A. Weinstein, Reduction of symplectic manifolds with symmetry, Reports on Math. Phys. 5 (1974), 121-130.

DIVISION OF SCIENCE AND MATHEMATICS, NEW YORK UNIVERSITY ABU DHABI, PO BOX 129188, ABU DHABI, UNITED ARAB EMIRATES.

DEPARTMENT OF MATHEMATICS, HONG KONG UNIV. OF SCI. AND TECH., CLEAR WATER BAY, KOWLOON, HONG KONG.