Large-N CP(N-1) sigma model on a finite interval and the renormalized string energy

We continue the analysis started in a recent paper of the large-N two-dimensional CP(N-1) sigma model, defined on a finite space interval L with Dirichlet (or Neumann) boundary conditions. Here we focus our attention on the problem of the renormalized energy density $\mathcal{E}(x,\Lambda,L)$ which is found to be a sum of two terms, a constant term coming from the sum over modes, and a term proportional to the mass gap. The approach to $\mathcal{E}(x,\Lambda,L)\to\tfrac{N}{4\pi}\Lambda^2$ at large $L\Lambda$ is shown, both analytically and numerically, to be exponential: no power corrections are present and in particular no L\"uscher term appears. This is consistent with the earlier result which states that the system has a unique massive phase, which interpolates smoothly between the classical weakly-coupled limit for $L\Lambda\to 0$ and the "confined" phase of the standard CP(N-1) model in two dimensions for $L\Lambda\to\infty$.Comment: LaTeX: 32 pages, 11 figures; V2: appendices E and F added and typos corrected; V3: grant information adde

Monopole-vortex complex in a theta vacuum

We discuss aspects of the monopole-vortex complex soliton arising in a hierarchically broken gauge system, G to H to 1, in a theta vacuum of the underlying G theory. Here we focus our attention mainly on the simplest such system with G=SU(2) and H=U(1). A consistent picture of the effect of the theta parameter is found both in a macroscopic, dual picture and in a microscopic description of the monopole-vortex complex soliton.Comment: 18 pages 3 figure

Development of a magnetically suspended, tetrahedron-shaped antenna pointing system

A magnetically suspended, tetrahedron-shaped antenna pointing system is proposed for use in a multibeam broadcasting satellite system in the future. The structure of this system is presented, along with its design concept and the functional test results which were obtained in a laser tracking system in the laboratory. According to these results, it has been confirmed that the system has many advantages over conventional systems and excellent performance

Large-NN CPN−1\mathbb{CP}^{N-1} sigma model on a finite interval: general Dirichlet boundary conditions

This is the third of the series of articles on the large-$N$ two-dimensional $\mathbb{CP}^{N-1}$ sigma model, defined on a finite space interval $L$ with Dirichlet boundary conditions. Here the cases of the general Dirichlet boundary conditions are studied, where the relative $\mathbb{CP}^{N-1}$ orientations at the two boundaries are generic, and numerical solutions are presented. Distinctive features of the $\mathbb{CP}^{N-1}$ sigma model, as compared e.g., to an $O(N)$ model, which were not entirely evident in the basic properties studied in the first two articles in the large $N$ limit, manifest themselves here. It is found that the total energy is minimized when the fields are aligned in the same direction at the two boundaries.Comment: Latex, 19 figure

Development of the sensitizer for generating higher-energy photons under diluted condition via the triplet-triplet annihilation-supported upconversion

It was previously reported that photon upconversion can occur in the solution containing anthracene and the Pt complex of octaethylporphyrin (PtOEP) via the triplet-triplet annihilation process. In this study, by employing the modified Pt complex of the dual anthracene-tethered porphyrin, DA-PtP as a sensitizer, it is demonstrated that shorter-wavelength light can be generated under diluted condition. We synthesized DA-PtP and compared upconversion properties by changing the type of sensitizers. Accordingly, it was shown that the photon upconversion proceeded with the xenon lamp (540 nm) in the presence of DA-PtP. Furthermore, it was found that the emission band in the shorter wavelength light in the near UV region was observed from the solution containing DA-PtP even under diluted condition. From the mechanistic investigation, it was proposed that the anthracene moieties in DA-PtP might inhibit to form agglomeration with the free anthracene. As a result, reabsorption of the higher-energy light generated from upconversion could be suppressed