41,783 research outputs found
Interpolation of bilinear operators and compactness
The behavior of bilinear operators acting on interpolation of Banach spaces
for the method in relation to the compactness is analyzed. Similar
results of Lions-Peetre, Hayakawa and Person's compactness theorems are
obtained for the bilinear case and the method.Comment: This work was published at "Nonlinear Analysis: Theory, Methods and
Applications, Volume 73, Issue 2, 2010, Pages 526-537". Since there are some
gaps in the original proof of Theorem 4.3, Here we give a new proof. For
this, we change the Lemma 4.
Temperature chaos is a non-local effect
Temperature chaos plays a role in important effects, like for example memory
and rejuvenation, in spin glasses, colloids, polymers. We numerically
investigate temperature chaos in spin glasses, exploiting its recent
characterization as a rare-event driven phenomenon. The peculiarities of the
transformation from periodic to anti-periodic boundary conditions in spin
glasses allow us to conclude that temperature chaos is non-local: no bounded
region of the system causes it. We precise the statistical relationship between
temperature chaos and the free-energy changes upon varying boundary conditions.Comment: 15 pages, 8 figures. Version accepted for publication in JSTA
The out-equilibrium 2D Ising spin glass: almost, but not quite, a free-field theory
We consider the spatial correlation function of the two-dimensional Ising
spin glass under out-equilibrium conditions. We pay special attention to the
scaling limit reached upon approaching zero temperature. The field-theory of a
non-interacting field makes a surprisingly good job at describing the spatial
shape of the correlation function of the out-equilibrium Edwards-Anderson Ising
model in two dimensions.Comment: 20 pages + 5 Figure
Why a Single-Star Model Cannot Explain the Bipolar Nebula of Eta Carinae
I examine the angular momentum evolution during the 1837-1856 Great Eruption
of the massive star Eta Carinae. I find that the new estimate of the mass blown
during that eruption implies that the envelope of Eta Car substantially
spun-down during the 20 years eruption. Single-star models, most of which
require the envelope to rotate close to the break-up velocity, cannot account
for the bipolar nebula (the Homunculus) formed from matter expelled in that
eruption. The kinetic energy and momentum of the Homunculus further constrains
single-star models. I discuss how Eta Car can fit into a unified model for the
formation of bipolar lobes where two oppositely ejected jets inflate two lobes
(or bubbles). These jets are blown by an accretion disk, which requires stellar
companions in the case of bipolar nebulae around stellar objects.Comment: ApJ, in press. New references and segments were adde
Douglas-FIR Bark. II. Isolation and Characterization of A Glucomannan
A glucomannan has been isolated from the holocellulose fraction of the inner bark of Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco], and its structure and physical constants have been determined. The molar ratio of o-mannose, d-glucose, and d-galactose was 2:1:0.3. The glucomannan was completely methylated and hydrolyzed. Gas-liquid chromatographic and mass spectrometric analyses showed the presence of 2,3,4,6-tetra-, 2,3,6-tri-, and 2,3-di-O-methyl-d-glucopyranose, 2,3,6-tri- and 2,3-di-O-methyl-d-mannopyranose, and 2,3,4,6-tetra-O-methyl-d-galactopyranose. The proposed glucomannan structure consists of a linear chain of β-d-(1 → 4)-linked mannose and glucose units with α-d-(1 → 6)-linked galactose as intermittent, single-unit branches. The structural and physical properties of this glucomannan place it within the alkali-soluble family of polysaccharides known to be contained in the wood of all gymnosperms
FeNi-based magnetoimpedance multilayers: Tailoring of the softness by magnetic spacers
The microstructure and magnetic properties of sputtered permalloy films and FeNi(170 nm)/X/FeNi(170 nm) (X=Co, Fe, Gd, Gd-Co) sandwiches were studied. Laminating of the thick FeNi film with various spacers was done in order to control the magnetic softness of FeNi-based multilayers. In contrast to the Co and Fe spacers, Gd and Gd-Co magnetic spacers improved the softness of the FeNi/X/FeNi sandwiches. The magnetoimpedance responses were measured for [FeNi/Ti(6 nm)] 2/FeNi and [FeNi/Gd(2 nm)] 2/FeNi multilayers in a frequency range of 1-500 MHz: for all frequencies under consideration the highest magnetoimpedance variation was observed for [FeNi/Gd(2 nm)] 2/FeNi multilayers. © 2012 American Institute of Physics
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