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Quantum State and Information Flow of Black Holes Unveiled

  • 조회. 509
  • 등록일. 2017.08.30
  • 작성자. Administrator

Quantum State and Information Flow of Black Holes Unveiled

- DGIST undergraduate students published a paper on international journal ‘Classical and Quantum Gravity’ suggesting a clue to reveal fundamentals of black holes -

DGIST announced that Noh Dong-joo, Park Hyo-sup, Oh Jung-hoon, Lee Duck-sang and Hwang Joon-ha (Supervisor: Professor Zoe Hee Seung), the seniors at the School of Undergraduate Studies, have suggested the clue to identify the quantum state and quantum information flow of black holes. 

After Stephen Hawking published the theory of "Hawking radiation" in 1975, which states ‘Black holes can be evaporated by thermal radiation", the problem of the information loss of black holes has become a big issue for theoretical physicists studying quantum mechanics and gravity. If the black hole can be evaporated completely, it is required to explain what happens to the information about the quantum state that created the black hole. If the information on the quantum state disappears, it is contrary to the basic foundation of quantum mechanics.

The research team has investigated the quantum status and quantum information flow of black holes by creating other ideas assuming that the evaporating black hole has a system with three parts. For instance, when the black hole evaporates, there would a residue which directly holds the quantum information or another case would be that the quantum information is discarded into a baby space formed in the black hole. 

If the system of a black hole has three parts, in addition to the radiation of the black hole, the information that is intertwined between the inside of the black hole and radiation must be considered and the research team has confirmed that it is clearly different from dividing the system into two parts.


Professor Zoe Hee Seung, who led the study, stated "The theoretical studies of black holes are usually abstract and mathematically complex. However, this study has reinterpreted these problems to a level that could be solved by MATLAB numerical computation. It will enable to review various proposals for the information loss of black holes more specifically in a similar way.” 

This study is published in "Classical and Quantum Gravity", an international journal of gravity and the theory of spacetime. It is unusual for undergraduate students actively participate in the research and publish a paper as the first authors, although undergraduate students sometimes take part in the publication of the international journals as assistant researchers.

DGIST"s UGRP (Undergraduate Group Research Program) has played a major role in the publication of this study. DGIST has introduced the UGRP for the first time in order to foster students" collaborative research skills and enhance mutual communication capabilities that are the foundation of convergence research. Under the UGRP, a group of some 5 junior and senior students themselves designs and implements projects. The program has four courses based on the nature of the research subject: ‘Francis Crick Course’, the transdisciplinary research program across basic sciences; ‘Jang Young-Sil Course’, the studies between basic science and engineering such as invention, technology optimization, and engineering-oriented projects; ‘Jeong Yak-Yong Course’, the studies between basic science and humanities and social science, focusing on science documentary production or science-related publications for example; and ‘Bill Gates Course’, the industry-university cooperation and science venture researches.