Does a black hole create a hologram copy of anything that touches it?

June 16, 2015

Simulated view of a black hole (credit: Alain Riazuelo of the French National Research Agency, via Wikipedia)

According to Samir Mathur. professor of physics at The Ohio State University, the recently proposed idea that black holes have “firewalls” that destroy all they touch is wrong. He believes that a black hole converts anything that touches it into a hologram — a near-perfect copy of itself that continues to exist just as before.

Mathur says he proves that in a open-access paper posted online to the arXiv preprint server. In fact, he says, our world could be captured by a black hole, and we wouldn’t even notice.

The debate hinges on a principle called complementarity, proposed by Stanford University physicist Leonard Susskind. Complementarity requires that any such hologram created by a black hole be a perfect copy of the original.

But mathematically, physicists on both sides of this debate have concluded that strict complementarity is not possible; that is to say, a perfect hologram can’t form on the surface of a black hole. But Mathur and his colleagues are comfortable with the idea, because they have since developed a modified model of complementarity, in which they assume that an imperfect hologram forms.

The information paradox

Physicist Stephen Hawking has famously said that the universe was imperfect from the very first moments of its existence. Without an imperfect scattering of the material created in the Big Bang, gravity would not have been able to draw together the atoms that make up galaxies, stars, the planets—and us.

This new dispute hinges on whether physicists can accept that black holes are imperfect, just like the rest of the universe. “There’s no such thing as a perfect black hole, because every black hole is different,” Mathur explained.

His comment refers to the resolution of the “information paradox,” a long-running physics debate in which Hawking eventually conceded that the material that falls into a black hole isn’t destroyed, but rather becomes part of the black hole. The black hole is permanently changed by the new addition. That means every black hole is a unique product of the material that happens to come across it.

Interestingly, one of the tenets of string theory is that our three-dimensional existence might actually be a hologram on a surface that exists in many more dimensions.

“If the surface of a black hole is a firewall, then the idea of the universe as a hologram has to be wrong,” Mathur said.  “It’s a simple question, really. Do you accept the idea of imperfection, or do you not?”


Abstract of A model with no firewall

We construct a model which illustrates the conjecture of fuzzball complementarity. In the fuzzball paradigm, the black hole microstates have no interior, and radiate unitarily from their surface through quanta of energy E∼T. But quanta with E≫T impinging on the fuzzball create large collective excitations of the fuzzball surface. The dynamics of such excitations must be studied as an evolution in superspace, the space of all fuzzball solution |Fi⟩. The states in this superspace are arranged in a hierarchy of `complexity’. We argue that evolution towards higher complexity maps, through a duality analogous to AdS/CFT, to infall inside the horizon of the traditional hole. We explain how the large degeneracy of fuzzball states leads to a breakdown of the principle of equivalence at the threshold of horizon formation. We recall that the firewall argument did not invoke the limit E≫T when considering a complementary picture; on the contrary it focused on the dynamics of the E∼Tmodes which contribute to Hawking radiation. This loophole allows the dual description conjectured in fuzzball complementarity