40,248 research outputs found
On real projective connections, V.I. Smirnov's approach, and black hole type solutions of the Liouville equation
We consider real projective connections on Riemann surfaces and corresponding
solutions of the Liouville equation. It is shown that these solutions have
singularities of special type (of a black hole type) on a finite number of
simple analytical contours. The case of the Riemann sphere with four real
punctures, considered in V.I. Smirnov's thesis (Petrograd, 1918), is analyzed
in detail.Comment: 13 pages, final versio
Equivalence of Geometric h<1/2 and Standard c>25 Approaches to Two-Dimensional Quantum Gravity
We show equivalence between the standard weak coupling regime c>25 of the
two-dimensional quantum gravity and regime h<1/2 of the original geometric
approach of Polyakov [1,2], developed in [3,4,5].Comment: 10 pages, late
Voice input/output capabilities at Perception Technology Corporation
Condensed resumes of key company personnel at the Perception Technology Corporation are presented. The staff possesses recognition, speech synthesis, speaker authentication, and language identification. Hardware and software engineers' capabilities are included
Raman Solitons and Raman spikes
Stimulated Raman scattering of a laser pump pulse seeded by a Stokes pulse
generically leaves a two-level medium initially at rest in an excited state
constituted of static solitons and radiation. The soliton birth manifests as
sudden very large variations of the phase of the output pump pulse. This is
proved by building the IST solution of SRS on the semi-line, which shows
moreover that initial Stokes phase flips induce Raman spikes in the pump output
also for short pulse experiments.Comment: RevTex file, 4 page
Ordering in spatially anisotropic triangular antiferromagnets
We investigate the phase diagram of the anisotropic spin-1/2 triangular
lattice antiferromagnet, with interchain diagonal exchange J' much weaker than
the intrachain exchange J. We find that fluctuations lead to a competition
between (commensurate) collinear antiferromagnetic and (zig-zag) dimer orders.
Both states differ in symmetry from the spiral order known to occur for larger
J', and are therefore separated by quantum phase transitions from it. The
zero-field collinear antiferromagnet is succeeded in a magnetic field by
magnetically-ordered spin-density-wave and cone phases, before reaching the
fully polarized state. Implications for the anisotropic triangular magnet
Cs_2CuCl_4 are discussed.Comment: 4 pages, 2 figures; v2: improved zero-field phase diagram, new
figure
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