Tokyo, Japan
Tokyo, Japan

Rikkyo University , also known as Saint Paul's University, is a private university, located in Ikebukuro, Tokyo.A leading liberal arts teaching and research institution, Rikkyo is the largest Anglican Christian affiliated university in Japan and is a member of the "Big Six" grouping of prominent private universities in Tokyo. The university is known for its supportive and student focused approach to academic study; encouraging all enrolled students to challenge themselves and discover their own innate potential in their chosen field of study. A philosophy symbolized by the motto "academy of freedom" ; urging students to reject preconceived limitations and to broaden their knowledge and appreciation of the essence of all things through advanced study. Wikipedia.

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Hikida Y.,Rikkyo University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2016

We study the breaking of gauge symmetry for higher spin theory on AdS4 dual to the 3d critical O(N) vector model. It was argued that the breaking is due to the change of boundary condition for a scalar field through a loop effect and the Goldstone modes are bound states of a scalar field and higher spin field. The masses of higher spin fields were obtained from the anomalous dimensions of dual currents at the leading order in 1/N, and we reproduce them from the O(N) vector model in the conformal perturbation theory. The anomalous dimensions can be computed from the bulk theory using Witten diagrams, and we show that the bulk computation reduces to the boundary one in the conformal perturbation theory. With this fact our computation provides an additional support for the bulk interpretation. © 2016 American Physical Society.

Kobayashi T.,Rikkyo University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2016

The null energy condition can be violated stably in generalized Galileon theories, which gives rise to the possibilities of healthy nonsingular cosmologies. However, it has been reported that in many cases cosmological solutions are plagued with instabilities or have some pathologies somewhere in the whole history of the universe. Recently, this was shown to be generically true in a certain subclass of the Horndeski theory. In this short paper, we extend this no-go argument to the full Horndeski theory and show that nonsingular models (with flat spatial sections) in general suffer from either gradient instabilities or some kind of pathology in the tensor sector. This implies that one must go beyond the Horndeski theory to implement healthy nonsingular cosmologies. © 2016 American Physical Society.

We show that 11-dimensional supergravity in Euclidean signature admits an exact classical solution with isometry corresponding to a three-dimensional scale-invariant field theory without conformal invariance. We also construct the holographic renormalization group flow that connects the known UV conformal fixed point and the new scale-invariant but not conformal fixed point. In view of holography, the existence of such classical solutions suggests that the topologically twisted M2-brane gauge theory possesses a scale-invariant but not conformal phase. © 2017 American Physical Society.

Takahashi D.,Rikkyo University
Journal of High Energy Physics | Year: 2011

We construct a boundary state for a class of analytic solutions in the Witten's open string field theory. The result is consistent with the property of the zero limit of a propagator's length, which was claimed in [19]. And we show that our boundary state becomes expected one for the perturbative vacuum solution and the tachyon vacuum solution. We also comment on possible presence of multi-brane solutions and ghost brane solutions from our boundary state. © 2011 SISSA.

Individuals of many avian and mammalian species produce antipredator calls when they encounter a predator. These calls often vary in acoustic structure depending on the type or level of predation risk, thereby eliciting the appropriate escape responses in conspecifics. Such complexity in communication may also be advantageous in situations in which animals recruit other individuals to mob predators because different risks may sometimes require different mobbing responses. I tested this idea in Japanese great tits, Parus major minor, which produce acoustically distinct mobbing calls for two different nest predators: 'chicka' calls for jungle crows, Corvus macrorhynchos, and 'jar' calls for Japanese rat snakes, Elaphe climacophora. A playback experiment revealed that adult great tits responded to different mobbing calls with qualitatively different behaviours: they scanned the horizon in response to 'chicka' calls and gazed towards the ground in response to 'jar' calls. These two responses help adults search for and detect the corresponding predators since crows fly to the nest and snakes approach from the ground. This study demonstrates that the mobbing calls of Japanese great tits transmit referential information about predator types and elicit the appropriate predator-searching behaviours in adults. © 2012 The Association for the Study of Animal Behaviour.

Irie M.,Rikkyo University | Fukaminato T.,Hokkaido University | Matsuda K.,Kyoto University | Kobatake S.,Osaka City University
Chemical Reviews | Year: 2014

Chemical bond rearrangement during the phototransformation induces electronic as well as geometrical structure changes of the molecules. The molecular structure changes can be applied to various photonic devices. The electronic structure changes can be applied to optical memory media and various photoswitching devices. On the other hand, the geometrical structure changes can be applied to light-driven actuators and others. The photochromic diarylethene was serendipitously discovered during the course of study on photoresponsive polymers a quarter of a century ago. Various types of polymers having photoisomerizable chromophores, such as spiropyran, azobenzene, or stilbene, in the side or main chains, have been prepared in an attempt to change their conformation by photoirradiation.

Terao F.,Rikkyo University | Morimoto M.,Rikkyo University | Irie M.,Rikkyo University
Angewandte Chemie - International Edition | Year: 2012

Limber but strong: Two-component mixed crystals of diarylethene derivatives exhibit reversible, rapid, and fatigue-resistant bending upon alternate irradiation with UV and visible light (see picture). The crystals showed reversible curling into a hairpin shape while remaining crystalline. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Irie M.,Rikkyo University
Photochemical and Photobiological Sciences | Year: 2010

Photochromism is characterized as a reversible colour change of a chemical species upon photoirradiation. Although vast numbers of photochromic molecules have been so far synthesized, molecules which exhibit thermally irreversible photochromic reactivity are limited within a few families of compounds. Among the thermally irreversible photochromic molecules, diarylethene derivatives are the most promising candidates for applications to opto-electronic devices because of their fatigue resistance, high sensitivity and rapid response. In this review, characteristic photochromic performances of the derivatives, detection and analysis of the photochromic reactions at a single-molecule level and application of the single-crystalline photochromism to molecular machinery will be described. © 2010 The Royal Society of Chemistry and Owner Societies.

The present invention aims to provide a thermoluminescent phosphor for obtaining a two-dimensional or three-dimensional dosimeter for measuring dose absorbed by biological tissues, the thermoluminescent phosphor exerting superior handleability, exhibiting superior biological tissue equivalence, and having superior precision. The aforementioned object is achieved by means of a method for producing a thermoluminescent phosphor, the method comprising a step A1 for mixing lithium tetraborate, boron oxide and manganese dioxide, a step A2 for firing the aforementioned mixture at 770 to 840 C., and a step A3 for obtaining the thermoluminescent phosphor comprising lithium triborate as a base material and manganese as a luminescent center present in the base material by further adding and mixing lithium tetraborate into the aforementioned fired product and then firing the mixture at 770 to 840 C., wherein the molar ratio between the lithium tetraborate and the boron oxide in the step A1 is 1:X (1

Japan Atomic Energy Agency, Rikkyo University, Mizuho Information and Research Institute | Date: 2012-08-06

A system computes the interaction energy between a plurality of fragments in a calculation object substance according to the fragment molecular orbital method. The energy of each fragment, the two-body interaction energy of each dimer including two fragments, and the three-body interaction energy of each trimer including three fragments are calculated. The two-body interaction energy of each dimer is corrected by adding, to the two-body interaction energy of the dimer, the contribution of the dimer in the three-body interaction energy of the trimer that includes the dimer.

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