If I write the following in stan file, then what priors are used by rstan::stan() ? In model block I do not write any distributions for parameters m,v.
I think for parameter m the constant function is used.
I think for parameter v the constant function which is one on the interval [o,\infty] and 0 on otherwise.

Or is it used the inverse gamma? I am not sure what priors are used?

i appreciate for rapid reply. I think “it doesn’t matter” means that the value in the endpoints of the interval never be chosen in numerical process. But I want to write some paper, so theoretically, I want to know it !! Thank you !!