CORRIGENDUM: Phase transition in the two-dimensional frustrated x-y model: scaling equations
The author establishes scaling equations for the two-dimensional x-y model with weak frustration using the electrostatic analogy of Kosterlitz and Thouless. In the limit of small disorder he finds a shift in the critical temperature Tc(x)-Tc(0)=-(Jx/kB)(2 pi 2- pi /2 ln 2x) and the exponents are unchanged from the pure values.
Two-level systems in a spin-glass model. I. General formalism and two-dimensional model
A spin-glass model with two-dimensional, isotropic spins (XY model) is studied. The model exhibits two-level systems (TLS) which are related to the sense of rotation of the spin direction. The two-dimensional version of the model is equivalent at low temperature to an Ising model with Coulomb interactions (which are logarithmic in two dimensions). However, this long-range effective interaction between TLS may be a special feature of two-dimensional spins. The model depends on a continuous parameter x and can reproduce, in particular, the 'Edwards-Anderson model', the 'Mattis model', and the 'odd model'.
Can Centauros or Chirons BE the First Observations of Evaporating Mini Black Holes
We argue that the signals expected from the evaporation of mini black holes — predicted in TeV-gravity models with large extra dimensions, and possibly produced in ultrahigh energy collisions in the atmosphere — are quite similar to the characteristics of the Centauro events, an old mystery of cosmic-ray physics.