I have an expression something like this $$\int_{\Omega_t} |\nabla_yu|^2 dy $$ and i want to change the variables via $y : \Omega \to \Omega_t $
$y= x+ tv(x)+ \frac{t^2}{2} w(x)$
Can someone help me to find the expression $$\int_{\Omega} ...... dx$$
I have tried but i have failed . Thanks in advance.
