4. Main result
metric matrix made of gauge field matrix
g := 2
(
E4 − ˆF−θ
)−1
− E4
Theorem
If the gauge field ˆF− is instanton,
then g is the Einstein metric
ˆF− = −ˆF− =⇒ R¯jk = 0
原 健太郎 (Tokyo University of Science,Math) 電磁気と重力のとある関係 10/2018 4 / 21
10. Gauss’s law,Amp´ere’s circuital law
Definition (Equations of motion)
Electromagnetic tensor E is
defined as
∂µF−
µν := ˜gµα∂αF−
µν = 0
where ˜g is a Minkowski metric.
Remark (Gauss’s law,Amp´ere’s circuital law )
∇ · E = 0, ∇ × B − ∂tE = 0
原 健太郎 (Tokyo University of Science,Math) 電磁気と重力のとある関係 10/2018 10 / 21
11. Gauss’s law for magnetism,Maxwell-Faraday equation
Definition (Bianchi identity)
Electromagnetic tensor E is
defined as
µνρσ∂ρF−
µν = 0
Remark (Gauss’s law for magnetism,Maxwell-Faraday equation)
∇ · B = 0, ∇ × E + ∂tB = 0
原 健太郎 (Tokyo University of Science,Math) 電磁気と重力のとある関係 10/2018 11 / 21
12. インスタントン
Remark
E = ±E, dE = 0 =⇒ d E = 0
Theorem
Assume
g := 2
(
E4 − ˆF−
θ
)−1
− E4
then
(
d ˆF−
= 0 ⇐=
)
ˆF−
= −ˆF−
=⇒ |g| = 1 (Ricci flatness)
原 健太郎 (Tokyo University of Science,Math) 電磁気と重力のとある関係 10/2018 12 / 21
17. 無限次元⇒有限次元
Definition (vector space)
C2
= {ae1 + be2|a, b ∈ C}
CN
= {a1e1 + a2e2 + · · · + aNeN|a1, · · · , aN ∈ C}
L2
(C) =
{ ∞∑
n=−∞
cneinx
cn ∈ C
}
Remark (2状態系)
L2
(
C3
)
−→ C2
, B
(
L2
(
C3
))
−→ B
(
C2
)
∼= M2C
Two-dimensional linear algebra
原 健太郎 (Tokyo University of Science,Math) 電磁気と重力のとある関係 10/2018 17 / 21
18. 量子 n 体系 (2状態系)
Remark (many-body system)
C2
−→
(
C2
)⊗n ∼= C2n
, B
(
C2
)
−→ M2nC
2n-dimensional linear algebra
Definition
ˆHψ = Eψ
where
ψ ∈
(
C2
)⊗n
, ˆH ∈ M2nC
原 健太郎 (Tokyo University of Science,Math) 電磁気と重力のとある関係 10/2018 18 / 21
19. k-ベクトル空間の圏
Definition (k-Vect as a category)
X ∈ Ob (k-Vect) :⇔ X:vector space on k
ˆH ∈ Hom
(
X, ˜X
)
:⇔ ˆH:linear mapping over k
Definition (tensor product⊗)
⊗ : km
× kn
−→ km×n
⊗ (ea, fb) := ea ⊗ fb
Remark
k1
⊗ X ∼= X
原 健太郎 (Tokyo University of Science,Math) 電磁気と重力のとある関係 10/2018 19 / 21
20. 強モノイド圏
Fact ((k-Vect, ⊗, k))
A, B, C ∈ Ob (k-Vect)
=⇒ (A ⊗ B) ⊗ C = A ⊗ (B ⊗ C)
A ⊗ k = k ⊗ A = A
Definition ((C, ⊗, I):strict monoidal category)
A, B, C ∈ Ob (C)
=⇒ (A ⊗ B) ⊗ C = A ⊗ (B ⊗ C)
A ⊗ I = I ⊗ A = A
原 健太郎 (Tokyo University of Science,Math) 電磁気と重力のとある関係 10/2018 20 / 21
21. 強モノイド圏の例
Example (Functor category)
(
CC
, ◦, id
)
Ob
(
CC
)
: functor from C to C
Ob
(
CC
)
id (identity functor)
(f ◦ g) ◦ h = f ◦ (g ◦ h)
f ◦ id = id ◦ f = f
原 健太郎 (Tokyo University of Science,Math) 電磁気と重力のとある関係 10/2018 21 / 21