vol. 84 | iTHES

Vol. 84, June 15th, 2015


  • Upcoming Events
  • Event report
  • Paper of the week

Paper of the week

N. Iizuka, A. Tanaka and S. Terashima


Exact Path Integral for 3D Quantum Gravity

From the Office

The office of iTHES assistant, Ms.Chikako Oota is situated at the second floor of the main research building, room # 246. The extension number is 3261. She will be at the office from 10 a.m. to 16 p.m.

Upcoming Events

"Symposium on the Present and Future of iTHES" originally planned on June 15 (Mon), 2015
is postponed until Fall or Winter of this year from various constraints. We will announce the new date as soon as decided. Thanks for your understanding.
Tetsuo Hatsuda

Event report

A workshop entitled as "2nd String Theory in Greater Tokyo” was held on June 9th at Nishina Hall. This workshop is a part of the series of workshops which are intended as the inter-institutional effort to promote the research of string theory in Tokyo and surrounding area, thus the tile of the workshop. The first workshop was inaugurated in January by the initiative of KIPMU http://www.ipmu.jp/webfm_send/1115 , with which iTHES has exchanged the agreement for mutual cooperation and held a symposium last year .
We have invited two active researchers, Dr. Masaki Shigemori (Kyoto University) and Dr. Michele del Zotto (Harvard University) . They delivered comprehensive presentations including reviews on the subject of black hole microstates and supersymmetric gauge theories, respectively. From iTHES, Akinori Tanaka of iTHES-MCC team explained his recent work (see below).
There were also several short talks by junior researchers. The event attracted about 40 participants.

Paper of the week

Definition of the theory of quantum gravity is one of famous outstanding problems in particle physics and astro physics. In our paper, we shed light into this important problem by considering 2+1 dimensional quantum gravity. This theory does not describe our real 3+1 dimensional space-time, however is interesting from the purely theoretical point of view. Based on recent understandings of mysterious and conjectural equivalence between gravity and quantum field theory, so-called AdS/CFT correspondence, it was conjectured that the partition function of pure AdS Einstein gravity in 2+1 dimension in quantum regime should coincide with so-called modular J-function, a partition function of certain CFT. We tried to calculate the partition function for the 2+1 pure AdS Einstein gravity by utilizing a recently developed technique, and arrived at the J-function from purely gravity side calculation.
In our calculation, we summed up all topologies which admit the asymptotically AdS feature . Typical examples for such space-time are Euclidean AdS and non-rotating BTZ black hole solution in the figure. This calculation needs a regularization, and we used so-called Rademacher summation which is a technology in number theory.
N. Iizuka, A. Tanaka and S. Terashima,
"Exact Path Integral for 3D Quantum Gravity"