22,581 research outputs found
Is Accurate Understanding of Global Warming Necessary to Promote Willingness to Sacrifice?
Although not definitive, the authors\u27 study suggests potential benefits from having a general public better informed about global climate change. They find, e.g., that accurate information appears to increase willingness to accept personal sacrifice
Thermodynamic properties of spin-1/2 transverse XY chain with Dzyaloshinskii-Moriya interaction: Exact solution for correlated Lorentzian disorder
We extend the consideration of the spin-1/2 transverse XY chain with
correlated Lorentzian disorder (Phys. Rev. B {\bf 55,} 14298 (1997)) for the
case of additional Dzyaloshinskii-Moriya interspin interaction. It is shown how
the averaged density of states can be calculated exactly. Results are presented
for the density of states and the transverse magnetization.Comment: 2 figure
Happy Hottentots : Cake - Walk
https://digitalcommons.library.umaine.edu/mmb-ps/2343/thumbnail.jp
Coupled Fluctuations near Critical Wetting
Recent work on the complete wetting transition has emphasized the role played
by the coupling of fluctuations of the order parameter at the wall and at the
depinning fluid interface. Extending this approach to the wetting transition
itself we predict a novel crossover effect associated with the decoupling of
fluctuations as the temperature is lowered towards the transition temperature
T_W. Using this we are able to reanalyse recent Monte-Carlo simulation studies
and extract a value \omega(T_W)=0.8 at T_W=0.9T_C in very good agreement with
long standing theoretical predictions.Comment: 4 pages, LaTex, 1 postscript figur
Depinning with dynamic stress overshoots: A hybrid of critical and pseudohysteretic behavior
A model of an elastic manifold driven through a random medium by an applied
force F is studied focussing on the effects of inertia and elastic waves, in
particular {\it stress overshoots} in which motion of one segment of the
manifold causes a temporary stress on its neighboring segments in addition to
the static stress. Such stress overshoots decrease the critical force for
depinning and make the depinning transition hysteretic. We find that the steady
state velocity of the moving phase is nevertheless history independent and the
critical behavior as the force is decreased is in the same universality class
as in the absence of stress overshoots: the dissipative limit which has been
studied analytically. To reach this conclusion, finite-size scaling analyses of
a variety of quantities have been supplemented by heuristic arguments.
If the force is increased slowly from zero, the spectrum of avalanche sizes
that occurs appears to be quite different from the dissipative limit. After
stopping from the moving phase, the restarting involves both fractal and
bubble-like nucleation. Hysteresis loops can be understood in terms of a
depletion layer caused by the stress overshoots, but surprisingly, in the limit
of very large samples the hysteresis loops vanish. We argue that, although
there can be striking differences over a wide range of length scales, the
universality class governing this pseudohysteresis is again that of the
dissipative limit. Consequences of this picture for the statistics and dynamics
of earthquakes on geological faults are briefly discussed.Comment: 43 pages, 57 figures (yes, that's a five followed by a seven), revte
Fluid adsorption near an apex: Covariance between complete and critical wetting
Critical wetting is an elusive phenomenon for solid-fluid interfaces. Using
interfacial models we show that the diverging length scales, which characterize
complete wetting at an apex, precisely mimic critical wetting with the apex
angle behaving as the contact angle. Transfer matrix, renormalization group
(RG) and mean field analysis (MF) shows this covariance is obeyed in 2D, 3D and
for long and short ranged forces. This connection should be experimentally
accesible and provides a means of checking theoretical predictions for critical
wetting.Comment: 4 pages, 1 figure, submitted to Physical Review Letter
Possible effects of charge frustration in NaCoO: bandwidth suppression, charge orders and resurrected RVB superconductivity
Charge frustration due to further neighbor Coulomb repulsion can have
dramatic effects on the electronic properties of NaCoO in the full
doping range. It can significantly reduce the effective mobility of the charge
carriers, leading to a low degeneracy temperature . Such
strongly renormalized Fermi liquid has rather unusual properties--from the
point of view of the ordinary metals with --but similar to
the properties that are actually observed in the NaCoO system. For
example, we show that the anomalous thermopower and Hall effect observed in
NaCoO may be interpreted along these lines. If the repulsion is
strong, it can also lead to charge order; nevertheless, away from the
commensurate dopings, the configurational constraints allow some mobility for
the charge carriers, i.e., there remains some ``metallic'' component. Finally,
the particularly strong bandwidth suppression around the commensurate
can help resurrect the RVB superconductivity, which would otherwise not be
expected near this high doping. These suggestions are demonstrated specifically
for a -like model with an additional nearest neighbor repulsion.Comment: 15 pages, 17 figure
Expansion dynamics of Lennard-Jones systems
The dynamics of the expansion of a Lennard-Jones system, initially confined
at high density and subsequently expanding freely in the vacuum, is confronted
to an expanding statistical ensemble, derived in the diluted quasi-ideal
Boltzmann approximation. The description proves to be fairly accurate at
predicting average one-body global observables, but important deviations are
observed in the configuration-space structure of the events. Possible
implications for finite expanding physical systems are outlined
Mapping the phase diagram of strongly interacting matter
We employ a conformal mapping to explore the thermodynamics of strongly
interacting matter at finite values of the baryon chemical potential .
This method allows us to identify the singularity corresponding to the critical
point of a second-order phase transition at finite , given information
only at . The scheme is potentially useful for computing thermodynamic
properties of strongly interacting hot and dense matter in lattice gauge
theory. The technique is illustrated by an application to a chiral effective
model.Comment: 5 pages, 3 figures; published versio
Scaling Law and Aging Phenomena in the Random Energy Model
We study the effect of temperature shift on aging phenomena in the Random
Energy Model (REM). From calculation on the correlation function and simulation
on the Zero-Field-Cooled magnetization, we find that the REM satisfies a
scaling relation even if temperature is shifted. Furthermore, this scaling
property naturally leads to results obtained in experiment and the droplet
theory.Comment: 8 pages, 7 figures, to be submitted to J. Phys. Soc. Jp
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