Hunting a fundamental theory of quantum gravity

The world of Bousso’s new theorem still starts from our universe in remarkable ways. For mathematical convenience, it has hypothesized that there is an unlimited variety of particles, an unrealistic prerequisite that causes some physicists to ask if this third layer combines reality (with its about 17 known particles) better than the second layer. “We don’t have an infinite number of quantum fields,” he said Edgar ShaghoulianPhysicist at the University of California, Santa Cruz.

However, for some experts, Bousso’s work offers a satisfactory denunciation of the history of the singularity of Penrose and the wall, despite his unrealistic abundance of particles. It establishes that singularity cannot be avoided, even in the space phase with slight reactions to quantum matter. “Only by adding small quantum corrections, it is not possible to prevent singularity,” said Penington. Wall and Bousso’s work “replies fairly definitively”.

The real singularity

But Bousso’s theorem does not yet guarantee that the singularity must form in our universe.

Some physicists hope that the blind alleys go somehow. What seems a singularity could actually connect somewhere else. In the case of a black hole, perhaps those light rays end up in another universe.

And the lack of a singularity of the Big Bang could imply that our universe began with a “great rebound”. The idea is that a previous universe, as it collapsed under the attraction of gravity, somehow crashed the formation of a singularity and instead bounced in a period of expansion. The physicists who are developing rebound theories often work in the second layer of onion, using the semiclasseic physics that uses Quantum effects of negative energy To get around the singularity required by Penrose and Hawking theorems. In light of the new theorems, the truths that their theories also violate the second generalized law will have to swallow the beach.

A physique that pursues rebounds, Surjeet Rajenndran Johns Hopkins University, he says he is undertaken. He underlines that not even the second generalized law is the evangelical truth. Refusing itself would make the singularity avoidable and the continuation of possible space-time.

Sympularity skeptics can also attract theory to the center of onion, in which space-time behaves in truly quantum ways, such as taking overlaps. There, nothing can be taken for granted. It becomes difficult to define the concept of the area, for example, so it is not clear what form the second law should assume, and therefore the new theorems will not have.

Bousso and similar physicists, however, suspects that a highly quantum arena without any notion of the area is equivalent to a dead end for a light radius, and therefore that something to recognize as a singularity should persist in the main theory and in our universe. The beginning of the cosmos and the heart of black holes would really mark the edges of the map in which the watches cannot appear and the space stops.

“Inside black holes, I’m sure there is a notion of singularity,” he said Net engelhardtA MIT physicist who worked with wall.

In this case, the fundamental theory of quantum gravity would not kill singularity but would demystify. This truest theory would allow physicists to ask questions and calculate significant answers, but the language of these questions and answers would change radically. Spatial quantities such as position, curvature and durability could be useless for the description of a singularity. There, where time ends, other quantities or concepts may have to take their place. “If I had to guess me,” said Penington, “whatever the quantum state describes the singularity itself does not have a notion of time”.

Original story reprinted with permission from Magazine how much, an independent editorial publication of Simons Foundation whose mission is to improve the public understanding of science by covering research developments and mathematical trends and physical and life sciences.