We have measured the temperature dependence of the thermal conductivities of Ge 2 Sb 2 Te 5 (GST) and ZnS-SiO 2 using a nano second thermoreflectance measurement system from room temperature to 500 -600 C. The specific heat capacities of these materials also have been determined from À130 to 500 C for GST and from room temperature to 600 C for ZnS-SiO 2 . The Debye temperature was obtained from specific heat capacity measurement. Using the obtained temperature dependence of the thermal conductivities, a temperature simulation inside a simple structured optical disk with and without considering its temperature dependence was carried out, and the difference in maximum temperature was approximate 80 C.

We have experimentally determined the temperature dependences of the refractive index and thermal conductivity for several optical disk materials from room temperature to 200–300°C. A novel system for obtaining thermal conductivity in the films is also introduced. As a demonstration, temperature simulation inside a simple-structured disk with and without considerating the temperature dependence of the refractive index at a 405 nm wavelength was carried out, and the difference was approximately 15°C at maximum temperature.

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A 6-dimensional grand unified theory with the compact space having the topology of a real projective plane, i.e., a 2-sphere with opposite points identified, is considered. The space is locally flat except for two conical singularities where the curvature is concentrated. One supersymmetry is preserved in the effective 4d theory. The unified gauge symmetry, for example SU(5) , is broken only by the non-trivial global topology. In contrast to the Hosotani mechanism, no adjoint Wilson-line modulus associated with this breaking appears. Since, locally, SU(5) remains a good symmetry everywhere, no UV-sensitive threshold corrections arise and SU(5)-violating local operators are forbidden. Doublettriplet splitting can be addressed in the context of a 6d N = 2 super Yang-Mills theory with gauge group SU(6). If this symmetry is first broken to SU(5) at a fixed point and then further reduced to the standard model group in the above non-local way, the two light Higgs doublets of the MSSM are predicted by the group-theoretical and geometrical structure of the model.

We discuss the calculation of Fermi liquid parameters for the Anderson impurity model. An earlier calculation of de ChPtel is extended to a finite f-f-Coulomb interaction U and corrections of order l/Nf are studied, where Nf is the degeneracy of the localised level in the Anderson model. The lack of momentum conservation in the impurity model is found to be a complication, since the low-lying excited states are not automatically orthogonal in approximate calculations. In low-order l/Nf calculations the impurity induced quasi-particle density of states is found to have a singularity at the Fermi energy. The origin of this singularity is traced. The complications in obtaining thermodynamic properties via the calculation of Fermi liquid parameters is contrasted to the accuracy obtained in a 'direct approach', in which the calculations are performed to orders (1/Nf)', (l/Nf)' and (1/NJ2.