"(metaphysic is about) the nature of things as they are in themselves, beyond our experience"
Immanuel Kant, long dead

What is there?

What is it like?

Metaphysic explores:

What exists? (What is real?)
What is the nature of things? (What is time, space, objects, and even identity?)
What is beyond the physical world? (Ideas like the mind, soul, or God.)

It asks big, abstract questions about what the universe is made of and how everything fits together.
The idea of metaphysics is to explore and understand the most basic, fundamental aspects of reality that go beyond what we can see, measure, or observe directly.

To academize it, these are the key areas:

Ontology: The study of being and existence. It asks: What kinds of things exist? For example, do numbers, ideas, and time exist in the same way physical objects do?
Identity and Change: What does it mean for something to stay the same over time? How can things change and still be the same thing?
Causality: What causes things to happen? How do events in the universe interact with each other?
Time and Space: What are time and space? Are they real entities or just concepts in our minds?
Free Will vs. Determinism: Do humans have free will, or is everything we do determined by past events?

Metaphysic is a branch of philosophy that deals with questions about the fundamental nature of reality.
To make it more understandable and because you are a visual we made refer to the idea of Plato about forms, he believed there were perfect, non-physical "forms" or ideas (like
the idea of a perfect circle or beauty) that exists beyond our physical world. The things we see are just the imperfect copies of these forms. Further I want to tell you about the
ideas of Kant towards the subject, in his observation he distinguished between the world as we experience it (phenomenon) and the world as it exists in itself (noumenon),
which we can never fully know.

In essence, metaphysics is the study of reality at its most abstract and general level, trying to understand the principles that underlie everything else in our world.

Or to say it in in different words: when you feel I am running out of toiletpaper and you buy some, that is metaphysic transferred into reality.
(maybe coming from manifestation, but let's not get into hocupocus, I didn't bring a tent and you still don't have a glass ball)

Why it might be interesting for your subject?

In metaphysical terms, the body is more than just a physical object; it is the site of identity, experience, and selfhood. In that sense I believe your performance can't escape the
exploration of personal identity, even if you don't make it your main subject — linked to that I refer to your background, or position of growing up, or your hobbies or whatever
whatever whatever - all that leads to you carrying (like every other normal human) more than only one identity with you. Metaphysical discussions around embodiment (what it
means to be a body) and identity raise questions about how we experience ourselves through our bodies and how others perceive us. Beside that, metaphysics is still physics
(at least from a linguist point) so it also deals with the nature of space: is it an objective container that exists independently of us, or is it shaped by the beings and objects within
it? In the context of this performance, the body’s interaction with space can be seen as a form of metaphysical inquiry, in a sense of, what defines what? Body --> Space or
Space --> Body? If you want to go hard on the subject, the performance could challenge the idea of space as a neutral backdrop, instead suggesting that space is dynamic,
alive, and constantly being shaped by those who move through it (not saying you're doing that, but I guess it's just common sense the thing with no-stagnation). If you would go
hard, this resonates with metaphysical questions about relational space — whether space is something independent of the entities within it, or if space itself changes based on
interactions and relationships (and imagine how beautiful it would be to scream in there). In general, what I find interesting are the metaphysical issues that arise in the context
of multimedia art, because our form of art challenges traditional ideas about perception, reality, and identity. Example? Joan Jonas explores through her approach of art clearly
identity and myth, how? By layering different forms of media to reflect multiple realities. Imagine how it is about performance itself... further: a multimedia performance
complicates the metaphysics of perception even more, the blending of different art forms represent an effort to express the complexity of reality, much like metaphysical
theories attempt to describe the underlying structure of the universe.

If you want to explore some literature (I recommend strongly the one of Kant):

Loux, M. J., & Crisp, T. M. (Eds.). (2017). Metaphysics: A contemporary introduction (4th ed.). Routledge. // is about ontology, identity and causality
van Inwagen, P., & Sullivan, M. (Eds.). (2023). The Oxford handbook of metaphysics. Oxford University Press. // is a collection of essays on various topics
Aristotle. (1998). Metaphysics (H. Lawson-Tancred, Trans.). Penguin Classics. (Original work published c. 350 B.C.E.) // the thing where he talks about the experience
Kant, I. (1998). Critique of pure reason (P. Guyer & A. W. Wood, Eds. & Trans.). Cambridge University Press. (Original work published 1781) // about the limit of human knowledge
Fine, K. (2001). The question of ontology. Philosophers' Imprint, 1(1), 1-30. // ontology in metaphysics in conflict with reality
Lowe, E. J. (2006). Metaphysical realism and the theory of truth. Philosophy and Phenomenological Research, 72(2), 343-365. // discusses if reality exists independently of us
Chalmers, D. J., Manley, D., & Wasserman, R. (Eds.). (2009). Metametaphysics: New essays on the foundations of ontology. Oxford University Press. // about the inquirement of itself