Comment by A_D_E_P_T | Hacker News Reader

Comment by A_D_E_P_T | Hacker News Reader

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It's nonsense.

See this comment on their previous paper: https://arxiv.org/abs/2306.07628

The authors of the comment show that the "gravitational pair-production" rate used in the work in OP comes from truncating the covariant heat-kernel (proper-time) expansion of the one-loop effective action at second order in curvature, an approximation that is valid only in weak-field regions where all curvature invariants satisfy |R| · ℓ² ≪ 1 (where ℓ is the Compton wavelength). When that same expression is pushed into the high-curvature interior of a neutron star -- where the inequalities fail by many orders of magnitude -- the series is no longer asymptotic and its early terms generate a spurious imaginary part. Because the paper's entire mass-loss mechanism and lifetime bound follow from that uncontrolled imaginary term, its conclusions collapse.

Simply put, it doesn't even correspond to known experiments. It's entirely driven by a narrow artefact and has no physical basis.

Naively speaking, these predictions seem like they should be very sensitive to all sorts of effects, some better understood than others. It's odd how many commenters here treat headlines like these as settled fact, instead of one team's calculations based on assumptions that may be wildly off.

The authors wrote a reply to that comment

https://arxiv.org/pdf/2308.12326

I think about how some relativists think you could see a Hawking Radiation like effect if you're accelerating

https://en.wikipedia.org/wiki/Unruh_effect

although the idealized case of endless acceleration implies a certain kind of horizon

https://en.wikipedia.org/wiki/Rindler_coordinates

maybe the horizon doesn't matter much,.

There's a lot wrong with that reply -- it mostly just shifts the goalposts without answering the central objections raised in the comment.

Much of the reply revolves around whether the mixed invariant G=E⋅B appears at leading or higher order in the QED Schwinger result. But the comment's critique used the constant-field Schwinger problem only as a check that the authors' master formula fails against a case with an exact answer; the real complaint is that the same failure occurs for curved-spacetime examples where the exact result is known to vanish. Debating G is fine, but you can't ignore the gravitational case either.

The reply repeatedly says the comment is "outside the realm of applicability" of the formula -- as though that were the comment's fault! But if the formula cannot survive the very checks the authors themselves hold up (Schwinger with B≠0, Ricci-flat space), the burden is on the authors to (severely) restrict their own claims, not on critics to ignore the failure modes.

Very strange prediction indeed, the object need an event horizon for hawking radiation to occur

Reply on news.ycombinator.com