5,473 research outputs found
On the adaptive advantage of always being right (even when one is not)
We propose another positive illusion – overconfidence in the generalisability of one’s theory – that fits with McKay & Dennett’s (M&D’s) criteria for adaptive misbeliefs. This illusion is pervasive in adult reasoning but we focus on its prevalence in children’s developing theories. It is a strongly held conviction arising from normal functioning of the doxastic system that confers adaptive advantage on the individual
Field tuned critical fluctuations in YFe2Al10: Evidence from magnetization, 27Al (NMR, NQR) investigations
We report magnetization, specific heat, and NMR investigations on YFe2Al10
over a wide range in temperature and magnetic field and zero field (NQR)
measurements. Magnetic susceptibility, specific heat and spin-lattice
relaxation rate divided by T (1/T1T) follow a weak power law (T^-0.4)
temperature dependence, which is a signature of critical fluctuations of Fe
moments. The value of the Sommerfeld-Wilson ratio and linear relation between
1/T1T and chi(T) suggest the existence of ferromagnetic correlations in this
system. No magnetic ordering down to 50 mK in Cp(T) and the unusual temperature
and field scaling of the bulk and NMR data are associated with a magnetic
instability which drives the system to quantum criticality. The magnetic
properties of the system are tuned by field wherein ferromagnetic fluctuations
are suppressed and a crossover from quantum critical to FL behavior is observed
with increasing magnetic field
Magnetotransport in the low carrier density ferromagnet EuB_6
We present a magnetotransport study of the low--carrier density ferromagnet
EuB_6. This semimetallic compound, which undergoes two ferromagnetic
transitions at T_l = 15.3 K and T_c = 12.5 K, exhibits close to T_l a colossal
magnetoresistivity (CMR). We quantitatively compare our data to recent
theoretical work, which however fails to explain our observations. We attribute
this disagreement with theory to the unique type of magnetic polaron formation
in EuB_6.Comment: Conference contribution MMM'99, San Jos
Traveling Wave Solutions of Advection-Diffusion Equations with Nonlinear Diffusion
We study the existence of particular traveling wave solutions of a nonlinear
parabolic degenerate diffusion equation with a shear flow. Under some
assumptions we prove that such solutions exist at least for propagation speeds
c {\in}]c*, +{\infty}, where c* > 0 is explicitly computed but may not be
optimal. We also prove that a free boundary hy- persurface separates a region
where u = 0 and a region where u > 0, and that this free boundary can be
globally parametrized as a Lipschitz continuous graph under some additional
non-degeneracy hypothesis; we investigate solutions which are, in the region u
> 0, planar and linear at infinity in the propagation direction, with slope
equal to the propagation speed.Comment: 40 pages, 1 figur
A Variational Principle for the Asymptotic Speed of Fronts of the Density Dependent Diffusion--Reaction Equation
We show that the minimal speed for the existence of monotonic fronts of the
equation with , and in
derives from a variational principle. The variational principle allows
to calculate, in principle, the exact speed for arbitrary . The case
when is included as an extension of the results.Comment: Latex, postcript figure availabl
A Nuclear Physics Program at the ATLAS Experiment at the CERN Large Hadron Collider
The ATLAS collaboration has significant interest in the physics of
ultra-relativistic heavy ion collisions. We submitted a Letter of Intent to the
United States Department of Energy in March 2002. The following document is a
slightly modified version of that LOI. More details are available at:
http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/SM/ionsComment: Letter of Intent submitted to the United States Department of Energy
Nuclear Physics Division in March 2002 (revised version
A model independent and rephase invariant parametrization of CP violation
The phenomenological description of the neutral B meson system is proposed in
terms of the fundamental CP-violating observables and within a rephasing
invariant formalism. This generic formalism can select the time-dependent and
time-integrated asymmetries which provide the basic tools to discriminate the
different kinds of possible CP-violating effects in dedicated experimental
B-meson facilities.Comment: 19 pages, Plain Te
Fast-slow asymptotic for semi-analytical ignition criteria in FitzHugh-Nagumo system
We study the problem of initiation of excitation waves in the FitzHugh-Nagumo
model. Our approach follows earlier works and is based on the idea of
approximating the boundary between basins of attraction of propagating waves
and of the resting state as the stable manifold of a critical solution. Here,
we obtain analytical expressions for the essential ingredients of the theory by
singular perturbation using two small parameters, the separation of time scales
of the activator and inhibitor, and the threshold in the activator's kinetics.
This results in a closed analytical expression for the strength-duration curve.Comment: 10 pages, 5 figures, as accepted to Chaos on 2017/06/2
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