Let $X:\Omega\longrightarrow \mathbb{R}$ be a random variable. Suppose we take $n$ "observations" (aka. "samples") from $X$, and we put them into an $n$-tuple $(a_1, .., a_n)$, where $a_i$ is the $i$-th observation.
Now suppose we take an $n$-tuple $(X_, ..., X)$, made of $n$ copies of our random variable $X$, and we sample it once, resulting in an $n$-tuple $(b_1, ..., b_n)$.
- Are these 2 processes mathematically equivalent?
- If equivalent, are there any mathematical advantages of taking one viewpoint over the other?
- Does it make sense to build vectors of random variables? Can we even call them vectors? Do they form a vector space?
Random variables are just functions of the space of states.
Sampling is just evaluating them.
Having $X(w_1), X(w_2), ..., X(w_n)$ is the same as having $(X(w_1), X(w_2), ..., X(w_n))$.
What is not the same is doing things like $(X(w), X(w), ..., X(w))$.