T-systems, Y-systems, and cluster algebras: Tamely laced case

The T-systems and Y-systems are classes of algebraic relations originally associated with quantum affine algebras and Yangians. Recently they were generalized to quantum affinizations of quantum Kac-Moody algebras associated with a wide class of generalized Cartan matrices which we say tamely laced. Furthermore, in the simply laced case, and also in the nonsimply laced case of finite type, they were identified with relations arising from cluster algebras. In this note we generalize such an identification to any tamely laced Cartan matrices, especially to the nonsimply laced ones of nonfinite type.Comment: 31 pages, final version to appear in the festschrift volume for Tetsuji Miwa, "Infinite Analysis 09: New Trends in Quantum Integrable Systems

Structure of seeds in generalized cluster algebras

We study generalized cluster algebras introduced by Chekhov and Shapiro. When the coefficients satisfy the normalization and quasi-reciprocity conditions, one can naturally extend the structure theory of seeds in the ordinary cluster algebras by Fomin and Zelevinsky to generalized cluster algebras. As the main result, we obtain formulas expressing cluster variables and coefficients in terms of c-vectors, g-vectors, and F-polynomials.Comment: 15 pages; v2:minor revision; v3:typos corrected, to appear in Pacific J. Mat

Wightman-Function Approach to the Relativistic Complex-Ghost Field Theory

The relativistic complex-ghost field theory is covariantly formulated in terms of Wightman functions. The Fourier transform of the 2-point Wightman function of a complex-ghost pair is explicitly calculated, and its spontaneous breakdown of Lorentz invariance is compared with that of the corresponding Feynman integral.Comment: 10 page

Unobservable Higgs Boson and Spontaneous Violation of Lorentz Invariance

The standard theory of elementary particle physics is modified in such a way that the Higgs boson becomes unobservable and Lorentz invariance is slightly violated at the level of the S-matrix. The basic technique of realizing these properties without violating the unitarity of the physical S-matrix is the use of the complex-ghost quantum field theory.Comment: 8 page