8,054 research outputs found
Can price transparency contribute to more affordable patient access to medicines?
No abstract available
Artinian Gorenstein algebras with linear resolutions
Fix a pair of positive integers d and n. We create a ring R and a complex G
of R-modules with the following universal property. Let P be a polynomial ring
in d variables over a field and let I be a grade d Gorenstein ideal in P which
is generated by homogeneous forms of degree n. If the resolution of P/I by free
P-modules is linear, then there exists a ring homomorphism from R to P such
that P tensor G is a minimal homogeneous resolution of P/I by free P-modules.
Our construction is coordinate free
A Hybrid Model of Neutrino Masses and Oscillations: Bulk Neutrinos in the Split-Fermion Scenario
Higher-dimensional models of neutrino physics with one or more right-handed
neutrinos in the bulk have attracted considerable attention in recent years.
However, a critical issue for such models is to find a way of introducing the
required flavor dependence needed for generating neutrino oscillations. In this
paper, we point out that a natural ``minimal'' framework that accomplishes this
can be constructed by combining the bulk-neutrino hypothesis for right-handed
neutrinos with the split-fermion scenario for left-handed neutrinos. This
combination leads to a unique flavor signature for neutrino phenomenology which
easily incorporates large flavor mixing angles. This hybrid scenario also has a
number of additional important features. For example, one previous difficulty
of the split-fermion scenario applied to neutrinos has been that the mass
matrix is exponentially sensitive to neutrino displacements within the brane.
However, in our hybrid scenario, the interactions between the brane and bulk
naturally convert this dependence from exponential to linear. Another important
feature is that our hybrid scenario provides its own natural regulator for
Kaluza-Klein sums. Thus, in our scenario, all Kaluza-Klein summations are
manifestly finite, even in cases with multiple extra dimensions. But most
importantly, our mechanism completely decouples the effective neutrino flavor
mixing angles from the sizes of the overlaps between the neutrino wavefunctions
within the brane. Thus, we are able to obtain large neutrino mixing angles even
when these neutrinos have significant spatial separations and their overlaps
vanish.Comment: 11 pages, LaTeX, 1 figur
A minimal model for short-time diffusion in periodic potentials
We investigate the dynamics of a single, overdamped colloidal particle, which
is driven by a constant force through a one-dimensional periodic potential. We
focus on systems with large barrier heights where the lowest-order cumulants of
the density field, that is, average position and the mean-squared displacement,
show nontrivial (non-diffusive) short-time behavior characterized by the
appearance of plateaus. We demonstrate that this "cage-like" dynamics can be
well described by a discretized master equation model involving two states
(related to two positions) within each potential valley. Non-trivial
predictions of our approach include analytic expressions for the plateau
heights and an estimate of the "de-caging time" obtained from the study of
deviations from Gaussian behaviour. The simplicity of our approach means that
it offers a minimal model to describe the short-time behavior of systems with
hindered dynamics.Comment: 8 pages, 6 figure
Separation of (3.14C) 3-Hydroxy.3-methylglutaric acid from (3_14C) 3-Hydroxy-3-methylglutaryl CoA using Sephadex G-15 column chromatography
A new method has been developed for the separation of (3- 14C) 3-Hydroxy-3-methylglutaric acid
from a (3-14C) 3-Hydroxy-3-methylglutaryl CoA preparation using Sephadex G-15 column chromatography.
This method is simple, rapid and is useful in studies where the preparation of (3_ 14C) 3-Hyd1'oxy-3-methylglutaryl
CoA is required to bef1'eef1'Om (3_ 14C) 3-Hydroxy-3-methylgluta1'ic acid contamination
Comment on "Why interference phenomena do not capture the essence of quantum theory" by Catani et al
It was recently argued by Catani et al that it is possible to reproduce the
phenomenology of the double-slit experiment with a deterministic, local, and
classical model (arXiv:2111.13727). The stated aim of their argument is to
falsify the claim made by Feynman (in his third book of Lectures on Physics)
that the double-slit experiment is "impossible, absolutely impossible, to
explain in any classical way" and that it "contains the only mystery" of
quantum mechanics. We here want to point out some problems with their argument,
and defend Feynman's position.Comment: 3 pages, no figures, comments welcom
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