Computer simulation supports 'holographic' theory describing a black hole

A research group composed of four researchers has tested numerically a "holographic" theory, which was conjectured to describe accurately the dynamical phenomena occurring in a black hole.

Masanori Hanada, Ph.D., an associate professor at Kyoto University; Yoshifumi Hyakutake, Ph.D., an associate professor at Ibaraki University; Goro Ishiki, Ph.D., an assistant professor at Kyoto University; and Jun Nishimura, Ph.D., an associate professor at KEK were the main people working on this project.

As a new approach to solve this problem, Juan Martin Maldacena, a professor of Princeton University proposed a theory which describes gravity including the center of the black hole. According to this theory, dynamical phenomena occurring in a curved space-time like black holes can be described by a theory on a flat space-time, just as a hologram can record the information of 3D objects on a plane.

In the present research, the mass of a black hole was computed on a computer based on Maldacena's theory, and the results were compared with the results obtained by approximate calculation based on conventional superstring theory, which incorporate the quantum gravity effects.

Denoting the number of elements composing the black hole by N, previous works mainly studied the case in which N is so large that the quantum gravity effects near the black hole can be neglected. In the case of small N, on the other hand, whether the theory really describes the black hole correctly was an open question.

Based on the observation that the two different theoretical results agree, it has been concluded that the results obtained by the calculation in Maldacena's theory include the quantum gravity effects correctly as the calculation in conventional superstring theory does.

This work tested Maldacena's theory concerning a new description of black holes using a "hologram." While previous works provided various tests under the situation in which the quantum gravity effects near the black hole can be neglected, this work made a step forward and succeeded in performing a test including the quantum gravity effects, which is considered a significant progress.

The obtained results strongly suggest that Maldacena's theory describes the interior of the black hole even in the case in which the quantum gravity effects near the black hole cannot be neglected.