March 1993 arXiv papers — page 6
Showing 501–504 of 504 papers
R. Brandenberger, V. Mukhanov, A. Sornborger
A theory of gravitation is constructed in which all homogeneous and isotropic solutions are nonsingular, and in which all curvature invariants are bounded. All solutions for which curvature invariants approach their limiting values approach de Sitter space. The action for this theory is obtained by a higher derivative modification of Einstein's theory. W
S. Mazumdar, F. Guo, D. Guo, K. -C. Ung
Extrapolations of numerical data obtained from finite cluster calculations to the infinite volume limit can often give incorrect results. We discuss four separate cases: (a) the intensity of the lowest two-photon absorption in the infinite polyene, (b) bond alternation in the infinite polyene, (c) Cooper type pairing in the simple Hubbard model, and (d) pair
C. Stephen Hellberg, E. J. Mele
We study the t-J model in one dimension by numerically projecting the true ground state from a Luttinger liquid trial wave function. We find the model exhibits Luttinger liquid behavior for most of the phase diagram in which interaction strength and density are varied. However at small densities and high interaction strengths a new phase with a gap to spin e
Magnetic-Field Induced First-Order Transition in the Frustrated XY Model on a Stacked Triangular Lattice
cond-matM. L. Plumer, A. Mailhot, A. Caillé
The results of extensive Monte Carlo simulations of magnetic-field induced transitions in the xy model on a stacked triangular lattice with antiferromagnetic intraplane and ferromagnetic interplane interactions are discussed. A low-field transition from the paramagnetic to a 3-state (Potts) phase is found to be very weakly first order with behavior suggestin