concepts of theoretical solid state physics

λ
ψ
0
gψ
0
g
(
x
)
ψ
0

r


R


i


I

k
s
(n+1)ana(n-1)a
x
n-1

φ
n
m
φ
n
φ(x)Continuum Limit
(n-1)a na (n+1)a
T

M


φ


S

S[φ]

x


t


L

T


φ


ε
η
(
x
,
t
)
(
x
,
t
)

φ

-
Φ Φ
+ x=vtx=-vt

m
A
m
B
(n-1)a na (n+1)a