Perform a taylor expansion in 3 dimensions in time on the time compontent of of $T^{\alpha \beta}(t - r + n^{i} y_{i})$ given that $r$ is a contstant and $n^{i} y_{i}$ is the scalar product of a normal vector $n$ with a position vector $y$.
I believe the formula is $\phi (\vec{r} + \vec{a}) = \sum^{\infty}_{n=0} \frac{1}{n!} (\vec{a}\cdot \nabla)^{n} \phi(\vec{r})$ in general and that the first term is $T^{\alpha \beta}(t -r)$ but would appreciate some other opinion about what the proceeding terms should be up to order $n=3$.
Cheers