the Buddhist concept of anatta (no-self) claims

Buddhist philosophy

Can you imagine everything around you is just a shadow of something else?

the Upanishadic concept of Brahman-Atman identity claims

Brahman-Atman identity posits the individual self (Atman) is identical to ultimate reality (Brahman)

Nominalism

Nominalism claims only particular things exist, universals are just names

Mind–body dualism

Mind–body dualism posits mental phenomena as non-physical

Śūnyatā

Śūnyatā means "emptiness" in Sanskrit

Epiphenomenalism

Epiphenomenalism posits that consciousness is a by-product of physical brain states