Distinguishing Hawking radiation from the Unruh effect in minimal‑structure derivations

Determine whether minimal or essential‑structure derivations of Hawking radiation (such as those based on affine‑parameter relations at null infinity) can, in principle and in practice, distinguish Hawking radiation from the Unruh effect, and specify criteria that unambiguously separate the two phenomena.

Background

The paper discusses ‘essential structure’ programs (e.g., Visser 2003; Barceló, Liberati, Sonego, Visser 2011) that aim to derive Hawking‑like radiation under minimal global assumptions, potentially without event or Killing horizons.

The author cautions that these approaches may blur the distinction between Hawking radiation and the Unruh effect, a nontrivial interpretive issue for the foundations of black hole thermodynamics.