The are infinite realms. However, there are only 2 distinct worlds or known material world and immaterial world (or life and existence beyond the known physical world or presently termed as spirit world). And which are interdependent and interconnected as parts of sum of parts of the greater whole or observable spectra-field and non-observable dark spectra-field are parts of universal unified spectra-field through universal intertwinement and entanglement process and mechanism. And as such, are irreducible.
Another way of saying is observable and non-observable spectra-field interaction (such as form-formless transition and transformation from form to formless, formless to form, form to form, and formless to formless) spectra-field are facilitated within and through universal unified spectra-field dynamic process and mechanism. A simple way of saying is dark spectra-field can transform and transition to ordinary spectra-field. And vice versa. And as well as observable and non-observable spectra-field can arise from universal spectra-field in both worlds or across realms and worlds. A simple way of saying if they are dynamic irreducible parts of sum of parts of the greater whole.
As a simple illustration: as entities, sentient, and realms in known impermanence physical and immaterial worlds growth or transform and evolve through universal process of being and becoming, their spectra-field (i.e. energy, entropy-negentropy, and information) also vary dynamically and transformatively on demand or material and non-immaterial spectra-field have to be allocated or provide. And facilitated accordingly through nature universal unified spectra-field process and mechanism of intertwinement and entanglement of parts of sum of parts of the greater whole.
A few related main steam and non-main stream exploration:
Toward Nature's Epistemic and Ontic - EPISTEMOLOGY OF LIFE AND ONTOLOGY OF EXISTENCE FOUNDATION AND INSTITUTE (epistemologyontologyfoundationinstitute.org)
Blog Posts - EPISTEMOLOGY OF LIFE AND ONTOLOGY OF EXISTENCE FOUNDATION AND INSTITUTE (epistemologyontologyfoundationinstitute.org)
Growing Dark Spectra-Field Applied Science - EPISTEMOLOGY OF LIFE AND ONTOLOGY OF EXISTENCE FOUNDATION AND INSTITUTE (epistemologyontologyfoundationinstitute.org)
TGD diary: Does dark matter induce formation of more dark matter? (matpitka.blogspot.com)
Transcendental Physics: EXPLORING CONSCIOUSNESS (erclosetphysics.com)
and among many others globally.
Epistemology of Life and Ontology of Existence Foundation and Institute