Scientific Definition of Aura.

[NoOne]

I'd say that the human Aura is an energy field, a form of electromagnetic radiation probably. It could also be related to Rupert Sheldrake's morphic field theory, which states that all living things (including cells and single-cell organisms) form according to an energetic blueprint, which directs the growth of cells individually, but also their forming into complex organisms. This morphic field supposedly exists even before an organism is fully formed, so in essence it expands outwards and exceeds the physical boundaries of the organism. That is very similar to what auras allegedly are, they're probably related or even the exact same thing.

Sheldrake has done many scientific experiments that prove the existence of Morphic fields, I think we can treat their existence and by extension, that of auras as empirically provable fact.