vol. 83 | iTHES

Vol. 83, June 8th, 2015


  • Announcement
  • Upcoming Events
  • Event report
  • Paper of the week

Paper of the week

Takuya Kanazawa, Yoshimasa Hidaka, Kazuhiko Kamikako, Toshifumi Noumi


Phonons, Pions and Quasi-Long-Range Order in Spatially Modulated Chiral Condensates

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.


Press Release (2015/06/08)

A theory of asymmetric invisible cloaking recently proposed by Dr. Masato Taki (iTHES-phys team), Dr. Tomohiro Amemiya (TIT) and their collaborators was just press-released (in Japanese) on June 8, 2015.

The paper is "Optical Lattice Model Towards Nonreciprocal Invisibility"
by T. Amemiya, M. Taki, T. Kanazawa, T. Hiratani, S. Arai
IEEE journal quantum electronics, vol.51, No. 3 pp.6100110 (2015).
This paper was selected for the cover page of this volume.

The abstract of the paper starts with the sentence:
"We propose the design theory of nonreciprocal invisibility cloaking for an optical camouflage device with unidirectional transparency in which a person in the cloak can see the outside but cannot be seen from the outside." Harry Potter's invisibility cloak can now be realized !?

Upcoming Events

2nd String Theory in Greater Tokyo
June 9th, 2015, 9:30-16:20
RIKEN, Nishina Hall
We invite the following two speakers:
Michele Del Zotto(Harvard Univ)
Masaki Shigemori(Kyoto Univ)
They will give pedagogical talks about forefront of sting theory.
We also have local and short talk speakers:
Akinori Tanaka (RIKEN)
Tetsuji Kimura (Tokyo Institute of Technology)
Tomoki Nosaka (Kyoto University)
Hironori Mori (Osaka University)
Yoshiki Sato (Kyoto University)
Hiroyuki Shimizu (Tokyo University)
Shotaro Shiba (Kyoto Sangyo University)
Sotaro Sugishita (Kyoto University)

Koji Hashimoto (Osaka Univ.)
"How to see internal space"
June 12 (Fri) 11:00-
Main Research bldg. 248
Is internal space a space
Internal space, namely, the field space on which some global symmetry (such as U(1) group) acts, is called "internal space" but I don't know precisely why it is called so. In this talk I will explore the question and will come to a certain conclusion, using our new result on general effective action of internal moduli space of domain walls.

"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

On June 4, 2015, Prof. Tomoyuki Higuchi (http://www.ism.ac.jp/~higuchi/ ), Director of The Institute of Statistical Mathematics (ISM) http://www.ism.ac.jp/index_e.html ,has given a talk on "Interaction, Integration, and Design: Key elements for success on promoting the interdisciplinary research" at the iTHES seminar.
First he explained the history of ISM started in 1944 and the central role being played by ISM in the field of Statistical Mathematics (which should not be confused with Mathematical Statistics) in Japan. This interdisciplinary field is now growing very rapidly due to the needs of analyzing the big data accumulated in various fields in natural sciences, economy, literatures, industries etc.
Then he explained his specialty, data assimilation, which is a synthesis tool to combine a numerical simulation and big data. Although the seminar started from 10:30 in the morning, the room was full of people in various fields ranging from particle physics to health science, and there were lively discussions about the role of mathematical approaches to the current issues to extract useful information from the big data.


Paper of the week

Inhomogeneous states of matter appear everywhere in nature, ranging from biological patterns to domain walls and vortices in condensed matter and particle physics. Whether a spatially modulated condensate is formed or not in high-density compact stars and which spatial order has the lowest energy is a subject that has a very long history. In QCD at high quark density, the problem can be studied by using an effective relativistic fermion model having the same global symmetry as QCD. Recently it was claimed, on the basis of mean-field theory, that chiral condensate should be modulated along one axis near the QCD critical point, in formal analogy to the smectic-A phase of liquid crystals.
In this paper we have analyzed long-wavelength fluctuations in this modulated phase with the Ginzburg-Landau expansion near the Lifshitz point, and obtained elastic energies for pions and phonons that appear as the Nambu-Goldstone modes for the breaking of spatial and internal symmetries. Our work shows that the modulation is unstable in the thermodynamic limit and should be replaced with a quasi-long-range order phase with algebraic correlations. Conditions under which the spatial order survives is also derived.

Y. Hidaka, K. Kamikado, T. Kanazawa and T. Noumi,
"Phonons, Pions and Quasi-Long-Range Order in Spatially Modulated Chiral Condensates,''