- #1
Chris.X
- 1
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Hi
I am struggling to justify
[tex] D(x-y) \approx e^{-i m t} [/tex] as [tex] t \rightarrow \infty [/tex]
from
[tex] \int dE \sqrt{E^2-m^2} e^{-i E t} [/tex].
I thought I might get some insight from discretizing, as
[tex] e^{-i m t} \sum_{n=0}^{\infty} \epsilon \sqrt{ n \epsilon ( 2 m + n \epsilon ) } e^{-i n \epsilon t} [/tex]
but I don't understand how to approximate or take the limit of the sum.
I also tried to work backwards from
[tex] G : (E^2-m^2)^{3/2} e^{-i E t} [/tex]
and replacing extra E's with d/dt's and ended up with a differential equation
for the result,
[tex] G = i [ t (d^2/dt^2 + m^2) + 3 d/dt ] D(x-y) [/tex]
but I am having trouble putting the pieces together to solve it.
Assistance would be greatly appreciated.
I am struggling to justify
[tex] D(x-y) \approx e^{-i m t} [/tex] as [tex] t \rightarrow \infty [/tex]
from
[tex] \int dE \sqrt{E^2-m^2} e^{-i E t} [/tex].
I thought I might get some insight from discretizing, as
[tex] e^{-i m t} \sum_{n=0}^{\infty} \epsilon \sqrt{ n \epsilon ( 2 m + n \epsilon ) } e^{-i n \epsilon t} [/tex]
but I don't understand how to approximate or take the limit of the sum.
I also tried to work backwards from
[tex] G : (E^2-m^2)^{3/2} e^{-i E t} [/tex]
and replacing extra E's with d/dt's and ended up with a differential equation
for the result,
[tex] G = i [ t (d^2/dt^2 + m^2) + 3 d/dt ] D(x-y) [/tex]
but I am having trouble putting the pieces together to solve it.
Assistance would be greatly appreciated.
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