81,856 research outputs found
Character-level Intra Attention Network for Natural Language Inference
Natural language inference (NLI) is a central problem in language
understanding. End-to-end artificial neural networks have reached
state-of-the-art performance in NLI field recently.
In this paper, we propose Character-level Intra Attention Network (CIAN) for
the NLI task. In our model, we use the character-level convolutional network to
replace the standard word embedding layer, and we use the intra attention to
capture the intra-sentence semantics. The proposed CIAN model provides improved
results based on a newly published MNLI corpus.Comment: EMNLP Workshop RepEval 2017: The Second Workshop on Evaluating Vector
Space Representations for NL
Microlensing Detections of Moons of Exoplanets
We investigate the characteristic of microlensing signals of Earth-like moons
orbiting ice-giant planets. From this, we find that non-negligible satellite
signals occur when the planet-moon separation is similar to or greater than the
Einstein radius of the planet. We find that the satellite signal does not
diminish with the increase of the planet-moon separation beyond the Einstein
radius of the planet unlike the planetary signal which vanishes when the planet
is located well beyond the Einstein radius of the star. We also find that the
satellite signal tends to have the same sign as that of the planetary signal.
These tendencies are caused by the lensing effect of the star on the moon in
addition to the effect of the planet. We determine the range of satellite
separations where the microlensing technique is optimized for the detections of
moons. By setting an upper limit as the angle-average of the projected Hill
radius and a lower limit as the half of the Einstein radius of the planet, we
find that the microlensing method would be sensitive to moons with projected
separations from the planet of for a Jupiter-mass planet, for a Saturn-mass planet, and for a Uranus-mass planet. We compare the
characteristics of the moons to be detected by the microlensing and transit
techniquesComment: 6pages, 6 figure
Induced Magnetic Ordering by Proton Irradiation in Graphite
We provide evidence that proton irradiation of energy 2.25 MeV on
highly-oriented pyrolytic graphite samples triggers ferro- or ferrimagnetism.
Measurements performed with a superconducting quantum interferometer device
(SQUID) and magnetic force microscopy (MFM) reveal that the magnetic ordering
is stable at room temperature.Comment: 3 Figure
Number-conserving interacting fermion models with exact topological superconducting ground states
We present a method to construct number-conserving Hamiltonians whose ground
states exactly reproduce an arbitrarily chosen BCS-type mean-field state. Such
parent Hamiltonians can be constructed not only for the usual -wave BCS
state, but also for more exotic states of this form, including the ground
states of Kitaev wires and 2D topological superconductors. This method leads to
infinite families of locally-interacting fermion models with exact topological
superconducting ground states. After explaining the general technique, we apply
this method to construct two specific classes of models. The first one is a
one-dimensional double wire lattice model with Majorana-like degenerate ground
states. The second one is a two-dimensional superconducting model,
where we also obtain analytic expressions for topologically degenerate ground
states in the presence of vortices. Our models may provide a deeper conceptual
understanding of how Majorana zero modes could emerge in condensed matter
systems, as well as inspire novel routes to realize them in experiment.Comment: 5 pages, 2 figures; supplement: 4 pages, 1 figur
Approximate input physics for stellar modelling
We present a simple and efficient, yet reasonably accurate, equation of
state, which at the moderately low temperatures and high densities found in the
interiors of stars less massive than the Sun is substantially more accurate
than its predecessor by Eggleton, Faulkner & Flannery. Along with the most
recently available values in tabular form of opacities, neutrino loss rates,
and nuclear reaction rates for a selection of the most important reactions,
this provides a convenient package of input physics for stellar modelling. We
briefly discuss a few results obtained with the updated stellar evolution code.Comment: uuencoded compressed postscript. The preprint are also available at
http://www.ast.cam.ac.uk/preprint/PrePrint.htm
The C-flash and the ignition conditions of type Ia supernovae
Thanks to a stellar evolution code able to compute through the
C-flash we link the binary population synthesis of single degenerate
progenitors of type Ia supernovae (SNe Ia) to their physical condition at the
time of ignition. We show that there is a large range of possible ignition
densities and we detail how their probability distribution depends on the
accretion properties. The low density peak of this distribution qualitatively
reminds of the clustering of the luminosities of Branch-normal SNe Ia. We
tighten the possible range of initial physical conditions for explosion models:
they form a one-parameter family, independent of the metallicity. We discuss
how these results may be modified if we were to relax our hypothesis of a
permanent Hachisu wind or if we were to include electron captures.Comment: 10 pages, 14 figures, MNRAS accepte
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