If in the box negative particles are repelling, but the others are not, then the system tends to go two different ways, but the geometry of spacetime suggests only one shortest way to go. So the negative energies are contrary to geometric nature of General Relativity.

But let us prove, that the negative energy particle is forbidden by

the so called energy conditions. Because the co-moving observer

reports negative energy, then the gravitational mass m of this particle

is negative. But the inertial mass can not be negative, because if

one tries to drag this particle with force, the particle must be

dragged. So F=-m a, from that is obvious, that p=-m v gamma, where

relativistic factor gamma=1/sqrt{1-v^2}. Therefore the Total energy is

E=-m gamma>0. So, this particle has positive energy. Therefore it can not

have negative gravitational mass. Then, the negative energies can

not exist.

Let me note for the following, that the uncertainty principle relates to the uncertainty, which rises from trying to measure positive energy with the measuring device.

Then, there is no Hawking radiation, and thus, the nature would be

time-reversible.

Let me note following on Ref. [Laura Mersini-Houghton, Backreaction of Hawking radiation on a gravitationally collapsing star I: Black holes?,

Phys.~Lett.~B\ {\bf 738}, 61–-7 (2014) arXiv:1406.1525. See

also the research continuation in arXiv:1409.1837.]

{Main problem}

There is wave-particle dualism, so one can assign to the wave the particle description. As did the David Bohm in his interpretation of quantum effects. Therefore, as I understood the theory under consideration, near collapsing star appear pairs with opposite energies (E, -E) due to the uncertainty principle. But the negative value can not hold for long, so the negative energy particle can escape into the collapsing matter. Then the positive energy particle becomes free. What is problem with that? 1) if negative energy particle do not annihilate with the star, it is not free, because there is no event-horizon prior to t=infinity. So it can not escape below the event horizon within all history of cosmos. 2) The negative energy particle has negative gravitational mass, so it is expected to repel from the star and the positive energy particle tries to hide inside the star. So, the star tends to be the source of negative energy. 3) If the negative energy particle would be not repelled, then inside the star will be mixture of positive and negative particles (which the vacuum fluctuations have produced), which would chancel out the Laura's stabilization of the collapse.

Other problems with Laura's contribution you see in

http://vixra.org/abs/1410.0182

I wonder, why non-collapsing star does not evaporate itself?

Friends, the discussion is more than welcomed!