ar X iv : c on d - m at / 9 80 13 22 v 2 2 0 M ar 1 99 8 Two - Dimensional Coulomb Systems on a Surface of Constant Negative Curvature

ar X iv : 0 80 2 . 25 80 v 1 [ m at h . G T ] 1 9 Fe b 20 08 3 - Dimensional Schlaefli Formula and Its Generalization

Several identities similar to the Schlaefli formula are established for tetrahedra in a space of constant curvature.

ar X iv : c on d - m at / 9 50 91 12 v 2 2 2 N ov 1 99 5 The Two - Dimensional Two - Component Plasma Plus Background on a Sphere : Exact Results

An exact solution is given for a two-dimensional model of a Coulomb gas, more general than the previously solved ones. The system is made of a uniformly charged background, positive particles, and negative particles, on the surface of a sphere. At the special value Γ = 2 of the reduced inverse temperature, the classical equilibrium statistical mechanics is worked out : the correlations and the ...

ar X iv : c on d - m at / 9 60 31 90 v 1 2 9 M ar 1 99 6 The Four - Dimensional XY Spin Glass

ar X iv : m at h - ph / 0 60 30 26 v 1 9 M ar 2 00 6 Effective models for excitons in carbon nanotubes 2 nd of February , 2006

We analyse the low lying spectrum of a model of excitons in carbon nanotubes. Consider two particles with a Coulomb self-interaction, placed on an infinitely long cylinder. If the cylinder radius becomes small, the low lying spectrum is well described by a one-dimensional effective Hamiltonian which is exactly solvable.

ar X iv : c on d - m at / 9 40 30 13 v 1 3 M ar 1 99 4 Nesting Mechanism for d - symmetry Superconductors ∗

A nested Fermi surface with nearly parallel orbit segments is found to yield a singlet d–wave superconducting state at high temperatures for a restricted range of the on–site Coulomb repulsion that avoids the competing spin density wave instability. The computed superconducting transition temperature drops dramatically as the nesting vector is decreased, in accord with recent photo–emission dat...