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Therefore, from the mathematical viewpoint, the problem consists of solv-
ing Eq. (11g) with the restriction Eq. (11f), which matches solving Eqs.
(11b) and (11d); in other words,
,
,
and
(12)
∇×
BEt
= ∂
/
∂
∇×
EBt
= −∂
/
∂
∇⋅
B
=
0
∇⋅
E
=
0
1
2
in the MKS system; remembering that
(
)
−
.
c
=
εμ
=
1
00
The Faraday matrix representation becomes
0
BBE
a
−−
⎡
⎤
: rows
z
y
x
⎢
⎥
−
B
0
B
−
E
⎢
⎥
z
x
y
⎡
ab
⎤
=
(13a)
F
⎣
⎦
⎢
⎥
BB
−
0
−
E
y
x
z
⎢
⎥
EEE
0
b
: columns
⎢
⎥
⎣
⎦
x
y
z
And with Eq. (11c), an associated matrix for the dual tensor can be
constructed:
0
EEB
−
⎡
⎤
z
y
x
⎢
⎥
−
E
0
E
B
⎢
⎥
z
x
y
*
ab
⎡
F
⎤ =
(13b)
⎣
⎦
⎢
EE B
BBB
−
0
⎥
y
x
z
⎢
⎥
−−−
0
⎢
⎥
⎣
⎦
x
y
z
Note that Eq. (13b) is obtained if we make the following changes to Eq.
(13a):
,
EB
(13c)
→−
BE
→
Therefore, it may come to mind that * executes operation Eq. (13c); then,
it is clear that
**
. Comparing Eqs. (11a) and (13a), we obtain the
relationship of the electric and magnetic fields with four-potential:
ar ar
FF
=−
,
B
(14)
E
=−∇ −∂
φ
A
/
∂
t
=∇×
A
, where
A
()
(
)
because
r
AA
=
,
φ
and
φ
are the magnetic and electric poten-
tials, respectively.
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