Tsukasa Tada

In this study, we examined consequences of unconventional time development of two-dimensional conformal field theory induced by the L ₁ and L ₋₁ operators, employing the formalism previously developed in a study of sine-square deformation. We discovered that the retainment of the Virasoro algebra requires the presence of a cut-off near the fixed points. The introduction of a scale by the cut-off makes it possible to recapture the formula for entanglement entropy in a natural and straightforward manner.

Sine-square deformation, a recently found modulation of the coupling strength in certain statistical models, is discussed in the context of two-dimensional (2D) conformal field theories (CFTs), with particular attention to open/closed string duality. This deformation is shown to be nontrivial and leads to a divergence in the worldsheet metric. The structure of the vacua of the deformed theory is also investigated. The approach advocated here may provide an understanding of string duality through the worldsheet dynamics.

We suggest that the Hermitian matrix models with resonant tunneling may exhibit novel criticality. Some features of the proposed criticality are explored. In particular, we argue that the new critical point is connected with the first-order transition.

NABESHIMA-DANTSU is the name of the first Japanese-made carpets which have been produced in the Nabeshima domain (Saga Prefecture) since the later Edo period. The NABESHIMA-DANTSU carpets have been woven from one kind of cotton, and have been dyed with various dyes and color fixatives. We analyzed pieces of the NABESHIMA-DANTSU carpets stored in the Saga Prefectural Museum and the Saga Prefectural Art Museum, by using PIXE method in order to detect dyeing methods used in them. We also analyzed dyes, color fixatives and cotton used in the traditional Japanese dyeing method. From the NABESHIMA-DANTSU carpets, small amounts of dyed and non-dyed samples were picked up and were analyzed by in-air PIXE system at Tohoku University. It was found that Fe and Cu are related to the parts dyed orange, and Al is related to the parts dyed green. The analysis of cotton dyed by the traditional Japanese method shows the similar results. It means that both colors in the NABESHIMA-DANTSU carpets were dyed by the traditional Japanese method which uses natural dyes. From literature documentation, it is considered that synthetic dyes were mainly used during the Taisho era. The present result shows that natural dyes might have been used in the Taisho era. In this research the PIXE method has proved to be very effective for the analysis of dyeing methods.

The detection efficiency of the submilli-PIXE camera was improved by installing a new X-ray detector with a smaller distance from specimens. The distortion of elemental images caused by position dependent detection efficiency was corrected by estimating the detection efficiency based on the geometrical configuration of the detection system. The detection efficiency of characteristic X-rays from heavy elements such as iron and bromine became from 11 to 23 times higher than the previous system. The signal to noise ratios was improved from 1.8 to 2.5 times higher and detection limit was also decreased from 1/8 to 1/6 compared to the previous system. The in-air submilli-PIXE camera with improved detection system can be useful to biological applications.

The nonperturbative aspects of string theory are explored for non-critical string in two distinct formulations, loop equations and matrix models. The