13,062 research outputs found
Enhancement of variation of fundamental constants in ultracold atom and molecule systems near Feshbach resonances
Scattering length, which can be measured in Bose-Einstein condensate and
Feshbach molecule experiments, is extremely sensitive to the variation of
fundamental constants, in particular, the electron-to-proton mass ratio
(m_e/m_p or m_e/Lambda_{QCD}, where Lambda_{QCD} is the QCD scale). Based on
single- and two-channel scattering model, we show how the variation of the mass
ratio propagates to the scattering length. Our results suggest that variation
of m_e/m_p on the level of 10^{-11}~10^{-14} can be detected near a narrow
magnetic or an optical Feshbach resonance by monitoring the scattering length
on the 1% level. Derived formulae may also be used to estimate the isotopic
shift of the scattering length
Prosthetic glenoid fixation: lateralisation of the centre of rotation of a fixed-fulcrum total shoulder replacement is not associated with suboptimal glenoid bone formation during a functionally-relevant loading protocol
Prosthetic glenoid fixation: lateralisation of the centre of rotation of a fixed-fulcrum total shoulder replacement is not associated with suboptimal glenoid bone formation during a functionally-relevant loading protocol
Lyapunov Spectra in SU(2) Lattice Gauge Theory
We develop a method for calculating the Lyapunov characteristic exponents of
lattice gauge theories. The complete Lyapunov spectrum of SU(2) gauge theory is
obtained and Kolmogorov-Sinai entropy is calculated. Rapid convergence with
lattice size is found.Comment: 7pp, DUKE-TH-93-5
Rank-ordered Multifractal Spectrum for Intermittent Fluctuations
We describe a new method that is both physically explicable and
quantitatively accurate in describing the multifractal characteristics of
intermittent events based on groupings of rank-ordered fluctuations. The
generic nature of such rank-ordered spectrum leads it to a natural connection
with the concept of one-parameter scaling for monofractals. We demonstrate this
technique using results obtained from a 2D MHD simulation. The calculated
spectrum suggests a crossover from the near Gaussian characteristics of small
amplitude fluctuations to the extreme intermittent state of large rare events.Comment: 4 pages, 5 figure
Two-Phase Annular Flow in Helical Coil Flow Channels in a Reduced Gravity Environment
A brief review of both single- and two-phase flow studies in curved and coiled flow geometries is first presented. Some of the complexities of two-phase liquid-vapor flow in curved and coiled geometries are discussed, and serve as an introduction to the advantages of observing such flows under a low-gravity environment. The studies proposed -- annular two-phase air-water flow in helical coil flow channels are described. Objectives of the studies are summarized
Analytical and experimental study of stratification and liquid-ullage coupling, 1 June 1964 - 31 May 1965
Closed-form solution for stratification of subcooled fluids in containers subjected to heating, and for liquid-ullage vapor couplin
Weak Hopf algebras corresponding to Cartan matrices
We replace the group of group-like elements of the quantized enveloping
algebra of a finite dimensional semisimple Lie algebra
by some regular monoid and get the weak Hopf algebra
. It is a new subclass of weak Hopf algebras
but not Hopf algebras. Then we devote to constructing a basis of
and determine the group of weak Hopf algebra
automorphisms of when is not a root of
unity.Comment: 21 page
Dynamics of a passive sliding particle on a randomly fluctuating surface
We study the motion of a particle sliding under the action of an external
field on a stochastically fluctuating one-dimensional Edwards-Wilkinson
surface. Numerical simulations using the single-step model shows that the
mean-square displacement of the sliding particle shows distinct dynamic scaling
behavior, depending on whether the surface fluctuates faster or slower than the
motion of the particle. When the surface fluctuations occur on a time scale
much smaller than the particle motion, we find that the characteristic length
scale shows anomalous diffusion with , where from numerical data. On the other hand, when the particle moves faster
than the surface, its dynamics is controlled by the surface fluctuations and
. A self-consistent approximation predicts that the
anomalous diffusion exponent is , in good agreement with simulation
results. We also discuss the possibility of a slow cross-over towards
asymptotic diffusive behavior. The probability distribution of the displacement
has a Gaussian form in both the cases.Comment: 6 pages, 4 figures, error in reference corrected and new reference
added, submitted to Phys. Rev.
A new broken U(1)-symmetry in extreme type-II superconductors
A phase transition within the molten phase of the Abrikosov vortex system
without disorder in extreme type-II superconductors is found via large-scale
Monte-Carlo simulations. It involves breaking a U(1)-symmetry, and has a
zero-field counterpart, unlike vortex lattice melting. Its hallmark is the loss
of number-conservation of connected vortex paths threading the entire system
{\it in any direction}, driving the vortex line tension to zero. This tension
plays the role of a generalized ``stiffness'' of the vortex liquid, and serves
as a probe of the loss of order at the transition, where a weak specific heat
anomaly is found.Comment: 5 pages, 3 figure
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