8,655 research outputs found
On the support of measures in multiplicative free convolution semigroups
In this paper, we study the supports of measures in multiplicative free
semigroups on the positive real line and on the unit circle. We provide
formulas for the density of the absolutely continuous parts of measures in
these semigroups. The descriptions rely on the characterizations of the images
of the upper half-plane and the unit disc under certain subordination
functions. These subordination functions are -transforms of infinitely
divisible measures with respect to multiplicative free convolution. The
characterizations also help us study the regularity properties of these
measures. One of the main results is that the number of components in the
support of measures in the semigroups is a decreasing function of the semigroup
parameter
Probing gauge-phobic heavy Higgs bosons at high energy hadron colliders
We study the probe of the gauge-phobic (or nearly gauge-phobic) heavy Higgs
bosons (GPHB) at high energy hadron colliders including the 14 TeV LHC and the
50 TeV Super Proton-Proton Collider (SppC). We take the process , and study it at the hadron level including simulating the jet
formation and top quark tagging (with jet substructure). We show that, for a
GPHB with GeV, can be determined by adjusting the value
of in the theoretical distribution to fit the observed
distribution, and the resonance peak can be seen at the SppC for
=800 GeV and 1 TeV.Comment: 6 pages, with 7 eps files for 7 figure
Widening of Protostellar Outflows: an Infrared Outflow Survey in Low Luminosity Objects
We present an outflow survey toward 20 Low Luminosity Objects (LLOs), namely
protostars with an internal luminosity lower than 0.2 Lsun. Although a number
of studies have reported the properties of individual LLOs, the reasons for
their low luminosity remain uncertain. To answer this question, we need to know
the evolutionary status of LLOs. Protostellar outflows are found to widen as
their parent cores evolve, and therefore, the outflow opening angle could be
used as an evolutionary indicator. The infrared scattered light escapes out
through the outflow cavity and highlights the cavity wall, giving us the
opportunity to measure the outflow opening angle. Using the
Canada-France-Hawaii Telescope, we detected outflows toward eight LLOs out of
20 at Ks band, and based on archival Spitzer IRAC1 images, we added four
outflow-driving sources from the remaining 12 sources. By fitting these images
with radiative transfer models, we derive the outflow opening angles and
inclination angles. To study the widening of outflow cavities, we compare our
sample with the young stellar objects from Arce & Sargent 2006 and Velusamy et
al. 2014 in the plot of opening angle versus bolometric temperature taken as an
evolutionary indicator.Our LLO targets match well the trend of increasing
opening angle with bolometric temperature reported by Arce & Sargent and are
broadly consistent with that reported by Velusamy et al., suggesting that the
opening angle could be a good evolutionary indicator for LLOs. Accordingly, we
conclude that at least 40% of the outflow-driving LLOs in our sample are young
Class 0 objects.Comment: Accepted for publication in AJ, 13 pages, 9 figure
Exploiting Sentence Embedding for Medical Question Answering
Despite the great success of word embedding, sentence embedding remains a
not-well-solved problem. In this paper, we present a supervised learning
framework to exploit sentence embedding for the medical question answering
task. The learning framework consists of two main parts: 1) a sentence
embedding producing module, and 2) a scoring module. The former is developed
with contextual self-attention and multi-scale techniques to encode a sentence
into an embedding tensor. This module is shortly called Contextual
self-Attention Multi-scale Sentence Embedding (CAMSE). The latter employs two
scoring strategies: Semantic Matching Scoring (SMS) and Semantic Association
Scoring (SAS). SMS measures similarity while SAS captures association between
sentence pairs: a medical question concatenated with a candidate choice, and a
piece of corresponding supportive evidence. The proposed framework is examined
by two Medical Question Answering(MedicalQA) datasets which are collected from
real-world applications: medical exam and clinical diagnosis based on
electronic medical records (EMR). The comparison results show that our proposed
framework achieved significant improvements compared to competitive baseline
approaches. Additionally, a series of controlled experiments are also conducted
to illustrate that the multi-scale strategy and the contextual self-attention
layer play important roles for producing effective sentence embedding, and the
two kinds of scoring strategies are highly complementary to each other for
question answering problems.Comment: 8 page
Topological crystalline antiferromagnetic state in tetragonal FeS
Integration between magnetism and topology is an exotic phenomenon in
condensed-matter physics. Here, we propose an exotic phase named topological
crystalline antiferromagnetic state, in which antiferromagnetism intrinsically
integrates with nontrivial topology, and we suggest such a state can be
realized in tetragonal FeS. A combination of first-principles calculations and
symmetry analyses shows that the topological crystalline antiferromagnetic
state arises from band reconstruction induced by pair checker-board
antiferromagnetic order together with band-gap opening induced by intrinsic
spin-orbit coupling in tetragonal FeS. The topological crystalline
antiferromagnetic state is protected by the product of fractional translation
symmetry, mirror symmetry, and time-reversal symmetry, and present some unique
features. In contrast to strong topological insulators, the topological
robustness is surface-dependent. These findings indicate that non-trivial
topological states could emerge in pure antiferromagnetic materials, which
sheds new light on potential applications of topological properties in
fast-developing antiferromagnetic spintronics.Comment: 8 pages, 6 figure
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