- #1
carllacan
- 274
- 3
Hi.
I can't for the life of me understand the math behind the SVEA. I graphically/intuitively understand what it means that the envelope varies slowly, but I can't connect that with the mathematical expression: $$ \left \vert \frac{\partial ^2 E_0}{\partial t ^2} \right \vert << \left \vert \omega\frac{\partial E_0}{\partial t}\right \vert $$
If the field is sinusoidal then the first derivative should simply add a factor of ω , so that $$ \left \vert \frac{\partial ^2 E_0}{\partial t ^2} \right \vert = \left \vert \omega\frac{\partial E_0}{\partial t}\right \vert $$
but instead the approximation says that <<. What am I missing?
THank you for your time.
I can't for the life of me understand the math behind the SVEA. I graphically/intuitively understand what it means that the envelope varies slowly, but I can't connect that with the mathematical expression: $$ \left \vert \frac{\partial ^2 E_0}{\partial t ^2} \right \vert << \left \vert \omega\frac{\partial E_0}{\partial t}\right \vert $$
If the field is sinusoidal then the first derivative should simply add a factor of ω , so that $$ \left \vert \frac{\partial ^2 E_0}{\partial t ^2} \right \vert = \left \vert \omega\frac{\partial E_0}{\partial t}\right \vert $$
but instead the approximation says that <<. What am I missing?
THank you for your time.