Examples of research and documentation are here (or will be).
Often the process of documentation becomes material for new work. This is part of a developing theoretical framework that I am calling hauntological (a little bit after Derrida but differant).
The dead speak through us, when we talk and when we write, and I have found that this is also true in performance. Ghosts can slip in and out (they do what they want because they're ghosts). There's more to it than that, of course.
Some recent work:
Manifesto: Theatre for the Dead in Global Performance Studies
Review of Patricia Ybarra's 'Latinx Theatre in the Times of Neoliberalism' in Hispanic Research Journal
Trance Art and Other Possessions (with Laura Gonzalez) in Else