Mr.Ian Hawke

Maybe you will explain to me,whence in the finite universe or in finite space [ Black Hole ] infinite gravity force ?,finite space can only have a finite force and similarly infinite force needs infinite space,as with our universe is finite-standard model and Big Bang,from where you took infinite force ?

The full answer to your question is too complicated for a quick response, unfortunately. However, you can think of it this way: gravitational collapse is what *creates* the Hawking radiation particles in the first place. Energy is being extracted from the inner part of the collapsing region and moved into the outer part; see Sabine Hassenfelder’s blog post for more details on that.

Why isn’t the inward pressure of the particles(created as a result of QFT) considered?If there are inward bound particles moving towards the centre of mass of the star,resulting in net pressure contribution (due to QFT particles) becoming zero? ]]>

That would make a lot more sense than my reading, but yeah: they do make it sound in the text like there’s direct transfer. And just to be plain, I’m willing to be wrong on this!

One good thing about begging for publicity, though: someone will likely do a more detailed recalculation than I have time or resources to do.

]]>What I think they’ve got is two matter sources; the “star” (a dust fluid) and the Hawking radiation (a null dust fluid). Both are minimally coupled to gravity, and couple to each other only indirectly via the spacetime. The equations of motion of the star are the standard conservation of stress-energy, which involves derivatives of the Hawking radiation. The Hawking radiation is provided by the (seemingly dodgy) ansatz, closing the system.

I interpret this as: energy transferred from spacetime to Hawking radiation, which “propagates out” (positive energy out and negative energy in), which effectively reduces the gravitational potential (or redistributes in further away from the origin), slowing the collapse of the fluid.

There’s some ways in which this is related to the “spontaneous scalarization” simulations of Barausse and Palenzuela (eg http://journals.aps.org/prd/abstract/10.1103/PhysRevD.89.044024). In the scalar-tensor model they’re using the ansatz leads to similar equations and some odd behaviour, but isn’t such an… emotive issue.

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