@tsujimotter
2018/09/23 #
#{n = 2x2 + y2 + 32z2 } =
1
2
#{n = 2x2 + y2 + 8z2 }
L(En, 1) =
4
p
n
a2
n
4
3
5
6
5, 6, 7, 13, 14, 15, 20, 21, 22, 23, 24, 28, 29, 30, 31, 34, 37,
38, 39, 41, 45, 46, 47, …
1, 2, 3, 4, 8, 9, 10, 11, 12, 16, 17, 18, 19, 25, 26, 27, 32, 33,
35, 36, 40, 42, 43, 44, …
=) n
n
n = 2x2
+ y2
+ 8z2
n = 2x2
+ y2
+ 32z2
(x, y, z)
(x, y, z)
Thm. Tunnel (1983)
( )BSD
(=
n
X, Y, Z
8
<
:
X2
+ Y 2
= Z2
XY
2
= n
n ()
X2
+ Y 2
= Z2
(X Y )2
= Z2
4n (X + Y )2
= Z2
+ 4n
(X2
Y 2
)2
= Z4
42
n2
✓
(X2
Y 2
)Z
8
◆2
=
✓
Z
2
◆6
n2
✓
Z
2
◆2
⇥Z2
/26
x :=
✓
Z
2
◆2
y :=
✓
(X2
Y 2
)Z
8
◆2
±2XY = ±4n
y2
= x3
n2
x
XY = 2n
•  n  
•  En
En : y2
= x3
n2
x
() En(Q)
BSD
E/Q : elliptic curve
rank E(Q) > 0 () ords=1 L(E, s) > 0
L(E, s) = 0
Thm. 1977
E/Q
rank E(Q) > 0 =) ords=1 L(E, s) > 0
n
() rank En(Q) > 0
BSD
=)
()()
L(En, 1) = 0
1. 
2. 
3.  Waldspurger
1.
L(f, s) =
1X
n=1
bnn s
Mellin
Mellin
つ
Mellin
L(En, s) gEn 2 32n2
f(z) =
1X
n=1
bnqn
2.
k/2 N k–1 N’
Sk/2(˜0(N), )
Shimura
! Mk 1(N0
, 2
)
N’ = N/2
Niwa 1975]
2 32
gE1 =
1X
m=1
bmqm
7 !
3/2 128
f =
1X
m=1
amqm
3. Waldspurger
( , 1983)
n
f =
X
amqm
2 S3/2(˜0(128)) Shimura(f) = g =
X
bmqm
L(En, 1) =
4
p
n
a2
n L(En, 1) = 0 an = 0
(Waldspurger, 1980, 1981)
k–1 L
k/2 q- 2
f
q = e2⇡iz
Rem. 1/2
f(z) = (⇥(z) ⇥(4z))(⇥(32z)
1
2
⇥(8z))⇥(2z) 2 S3/2(˜0(128)
(8z))⇥(2z) 2 S3/2(˜0(128))
⇥(z) :=
X
n2Z
qn2
f(z) = (⇥(z) ⇥(4z))(⇥(32z)
1
2
⇥(8z))⇥(2z)
= ⇥(z)⇥(32z)⇥(2z)
1
2
⇥(z)⇥(8z)⇥(2z)
⇥(4z)⇥(32z)⇥(2z) +
1
2
⇥(4z)⇥(8z)⇥(2z)
=
X
x,y,z
q2x2
+y2
+32z2 1
2
X
x,y,z
q2x2
+y2
+8z2
X
x,y,z
q2x2
+4y2
+32z2
+
1
2
X
x,y,z
q2x2
+4y2
+8z2
an = #{n = 2x2
+ y2
+ 32z2
}
1
2
#{n = 2x2
+ y2
+ 8z2
}
#{n = 2x2
+ 4y2
+ 32z2
} +
1
2
#{n = 2x2
+ 4y2
+ 8z2
}
n : 0
() #{n = 2x2
+ y2
+ 32z2
} =
1
2
#{n = 2x2
+ y2
+ 8z2
}
an = 0
=) n
n
n = 2x2
+ y2
+ 8z2
n = 2x2
+ y2
+ 32z2
(x, y, z)
(x, y, z)
Thm. Tunnel (1983)
( )BSD
(=
N.
(2006)
–  1
–  3 3.3
–  4 4.4
7
7
✓
35
12
◆2
+
✓
24
5
◆2
=
30625 + 82944
3600
=
✓
337
60
◆2
1
2
·
35
12
·
24
5
= 7
157
=)
n
n
(x, y, z)
(x, y, z)
Thm. Tunnel (1983)
( )BSD
n = 8x2
+ 2y2
+ 64z2
n = 8x2
+ 2y2
+ 16z2
=)

合同数問題と保型形式

  • 1.
    @tsujimotter 2018/09/23 # #{n =2x2 + y2 + 32z2 } = 1 2 #{n = 2x2 + y2 + 8z2 } L(En, 1) = 4 p n a2 n
  • 3.
  • 4.
    5, 6, 7,13, 14, 15, 20, 21, 22, 23, 24, 28, 29, 30, 31, 34, 37, 38, 39, 41, 45, 46, 47, … 1, 2, 3, 4, 8, 9, 10, 11, 12, 16, 17, 18, 19, 25, 26, 27, 32, 33, 35, 36, 40, 42, 43, 44, …
  • 5.
    =) n n n =2x2 + y2 + 8z2 n = 2x2 + y2 + 32z2 (x, y, z) (x, y, z) Thm. Tunnel (1983) ( )BSD (=
  • 7.
    n X, Y, Z 8 < : X2 +Y 2 = Z2 XY 2 = n n ()
  • 8.
    X2 + Y 2 =Z2 (X Y )2 = Z2 4n (X + Y )2 = Z2 + 4n (X2 Y 2 )2 = Z4 42 n2 ✓ (X2 Y 2 )Z 8 ◆2 = ✓ Z 2 ◆6 n2 ✓ Z 2 ◆2 ⇥Z2 /26 x := ✓ Z 2 ◆2 y := ✓ (X2 Y 2 )Z 8 ◆2 ±2XY = ±4n y2 = x3 n2 x XY = 2n
  • 9.
    •  n   • En En : y2 = x3 n2 x () En(Q)
  • 10.
    BSD E/Q : ellipticcurve rank E(Q) > 0 () ords=1 L(E, s) > 0 L(E, s) = 0 Thm. 1977 E/Q rank E(Q) > 0 =) ords=1 L(E, s) > 0
  • 11.
    n () rank En(Q)> 0 BSD =) ()() L(En, 1) = 0
  • 12.
  • 13.
    1. L(f, s) = 1X n=1 bnns Mellin Mellin つ Mellin L(En, s) gEn 2 32n2 f(z) = 1X n=1 bnqn
  • 14.
    2. k/2 N k–1N’ Sk/2(˜0(N), ) Shimura ! Mk 1(N0 , 2 ) N’ = N/2 Niwa 1975] 2 32 gE1 = 1X m=1 bmqm 7 ! 3/2 128 f = 1X m=1 amqm
  • 15.
    3. Waldspurger ( ,1983) n f = X amqm 2 S3/2(˜0(128)) Shimura(f) = g = X bmqm L(En, 1) = 4 p n a2 n L(En, 1) = 0 an = 0 (Waldspurger, 1980, 1981) k–1 L k/2 q- 2
  • 16.
    f q = e2⇡iz Rem.1/2 f(z) = (⇥(z) ⇥(4z))(⇥(32z) 1 2 ⇥(8z))⇥(2z) 2 S3/2(˜0(128) (8z))⇥(2z) 2 S3/2(˜0(128)) ⇥(z) := X n2Z qn2
  • 17.
    f(z) = (⇥(z)⇥(4z))(⇥(32z) 1 2 ⇥(8z))⇥(2z) = ⇥(z)⇥(32z)⇥(2z) 1 2 ⇥(z)⇥(8z)⇥(2z) ⇥(4z)⇥(32z)⇥(2z) + 1 2 ⇥(4z)⇥(8z)⇥(2z) = X x,y,z q2x2 +y2 +32z2 1 2 X x,y,z q2x2 +y2 +8z2 X x,y,z q2x2 +4y2 +32z2 + 1 2 X x,y,z q2x2 +4y2 +8z2
  • 18.
    an = #{n= 2x2 + y2 + 32z2 } 1 2 #{n = 2x2 + y2 + 8z2 } #{n = 2x2 + 4y2 + 32z2 } + 1 2 #{n = 2x2 + 4y2 + 8z2 } n : 0 () #{n = 2x2 + y2 + 32z2 } = 1 2 #{n = 2x2 + y2 + 8z2 } an = 0
  • 19.
    =) n n n =2x2 + y2 + 8z2 n = 2x2 + y2 + 32z2 (x, y, z) (x, y, z) Thm. Tunnel (1983) ( )BSD (=
  • 20.
  • 22.
  • 23.
  • 24.
  • 25.
    =) n n (x, y, z) (x,y, z) Thm. Tunnel (1983) ( )BSD n = 8x2 + 2y2 + 64z2 n = 8x2 + 2y2 + 16z2 =)