Quantum space monster leaps from a gravity well

GRAVITY may have the power to create quantum monsters. A strong gravitational field can induce a runaway effect in quantum fluctuations in apparently empty space, resulting in a burgeoning concentration of energy that may explode stars or create black holes. So say Daniel Vanzella and William Lima at the University of São Paulo in Brazil.

Quantum phenomena are not thought to have any significant influence over processes on the astrophysical scale, such as the compression of gas clouds into stars. That's the domain of gravity, which in turn is not supposed to be much affected by quantum events, like an elephant unaware of the microbes on its skin. In only a few exotic cases, such as singularities inside black holes, do gravity and quantum-level forces influence the same processes.

Gravity is not supposed to feel quantum events, like an elephant unaware of the microbes on its skin

Now calculations by Vanzella and Lima suggest gravity can trigger a powerful reaction in the fluctuating quantum fields of forces in apparently empty space, and that this reaction may be enough to influence the evolution of large objects like stars.

According to the uncertainty principle, virtual particles quickly pop in and out of existence throughout the vacuum of space. The pair calculate that a sufficiently powerful gravitational field, such as that created by a dense object like a neutron star, could create a region near the star where these virtual particles become densely packed. Their calculations suggest that the overall energy density of this region will grow exponentially until it dwarfs the energy of the object that generated the gravitational field - a monster of virtual particles that exceeds the strength of its creator.

What that monster could do is still unknown, but Vanzella and Lima speculate that the amassed energy could conceivably explode a neutron star, collapse it into a black hole, or some combination of the two.

However, none of the quantum fields based on known forces, such as electromagnetism, would be capable of causing a neutron star to collapse. Only an as-yet undiscovered quantum field would react to the gravity of a neutron star.

Nevertheless, the pair say that known quantum fields may have an influence on astrophysical processes if they were triggered by gravitational effects on much larger scales - across clusters of galaxies or in superclusters, for example (Physical Review Letters, vol 104, p 161102).

David Toms at the University of Newcastle, UK, is intrigued by the idea. "It is surprising that it was not noted earlier," he says.

Paul Anderson of Wake Forest University in Winston-Salem, North Carolina, is also impressed by the pair's demonstration that quantum fields may occasionally rival gravity as the dominant force on large scales. But he says it is unclear whether the process could have significant astrophysical effects.

Fuente: newscientist.com