2,059 research outputs found
Unipotent representations of real classical groups
Let be a complex orthogonal or complex symplectic group, and let
be a real form of , namely is a real orthogonal group, a
real symplectic group, a quaternionic orthogonal group, or a quaternionic
symplectic group. For a fixed parity , we
define a set of nilpotent
-orbits in (the Lie algebra of ). When
is the parity of the dimension of the standard module of , this is the set of the stably trivial special nilpotent orbits, which
includes all rigid special nilpotent orbits. For each , we construct all unipotent
representations of (or its metaplectic cover when is a real symplectic
group and is odd) attached to via the method of theta
lifting and show in particular that they are unitary
Bounded-Distortion Metric Learning
Metric learning aims to embed one metric space into another to benefit tasks
like classification and clustering. Although a greatly distorted metric space
has a high degree of freedom to fit training data, it is prone to overfitting
and numerical inaccuracy. This paper presents {\it bounded-distortion metric
learning} (BDML), a new metric learning framework which amounts to finding an
optimal Mahalanobis metric space with a bounded-distortion constraint. An
efficient solver based on the multiplicative weights update method is proposed.
Moreover, we generalize BDML to pseudo-metric learning and devise the
semidefinite relaxation and a randomized algorithm to approximately solve it.
We further provide theoretical analysis to show that distortion is a key
ingredient for stability and generalization ability of our BDML algorithm.
Extensive experiments on several benchmark datasets yield promising results
A combinatorial characterization of the annihilator varieties of highest weight modules for classical Lie algebras
Let be a classical Lie algebra. Let be a highest
weight module of with highest weight , where
is half the sum of positive roots. In 1985, Joseph proved that the
associated variety of a primitive ideal is the Zariski closure of a nilpotent
orbit in . In this paper, we will give some combinatorial
characterizations of the annihilator varieties of highest weight modules for
classical Lie algebras. In fact, we will give two algorithms, i.e., bipartition
algorithm and partition algorithm.Comment: 40page
Fourier-Jacobi models of Deligne-Lusztig characters and depth zero local descent for unitary groups
In this paper, we deduce explicit multiplicity formulas of the Fourier-Jacobi
model for Deligne-Lusztig characters of finite symplectic groups, unitary
groups, and general linear groups. We then apply these results to deduce the
explicit depth zero local descent (\`a la Soudry and Tanay) for -adic
unitary groups. The result is a concrete example in the context of non-tempered
Gan-Gross-Prasad program.Comment: 31 pages. Comments are welcom
Polymorphisms of CYP1A1 I462V and GSTM1 genotypes and lung cancer susceptibility in Mongolian
Aim: To study the genotype of cytochrome P450 1A1(CYP1A1) I462V and glutathions S-transferase M1( GSTM1) and the relationship of the genetic polymorphism of them with the susceptibility of lung cancer in Mongolia of China. 

Methods: Allele-specific PCR and a multiplex PCR were employed to identify the genotypes of I462V of CYP1A1 and GSTM1 in a case-control study of 210 lung cancer patients with bronchoscopy diagnosis and 210 matched controls free of malignancy.

Results: The frequencies of the variant CYP1A1(Val/Val) genotypes and GSTM1(-) in lung cancer groups were higher than that in control groups (15.24% vs 7.4% and 56.67% vs 40.95% ). The individuals who carried with CYP1A1(Val/Val) or GSTM1(-) genotype had a significantly higher risk of lung cancer, the OR is 2.56 and 1.89 respectively. Stratified histologically the relative risk increased to 2.6 - fold when the patients carried with two valine alleles than the ones carried one valine allele in cases of SCC. GSTM1(-) genotype is the risk factor of SCC (OR=2.39) and AC(OR=2.16). The presence of at least one Val allele of CYP1A1 and GSTM1(-), the risk of lung cancer was increased, the OR was 4.15 for one Val allele and GSTM1(-) and 2.67 for two Val alleles and GSTM1 Considering ages and smoking status, the risk of lung cancer increased when the age less than 50 who carried with CYP1A1 valine (one or two) alleles or the age during the 51 to 65 who carried with GSTM1(-) genotype. The light smokers with CYP1A1 valine alleles and GSTM1(-) have a high risk for lung cancer. No association was found between the light and heavy drinkers with the susceptibility of lung cancer and the genetic polymorphisms of CYP1A1 I462V and GSTM1(-). 

Conclusion: The valine allele of CYP1A1 was the risk factors of lung cancer especially for SCC and GSTM1(-) also was the risk factor of lung cancer and especially for SCC and AC of Mongolian, China. Light smoking has a influence each other with genotype of CYP1A1 I462V and GSTM1(-) and susceptibility of lung cancer. No relationship was found between the susceptibility of lung cancer and drinkers with genetic polymorphisms of CYP1A1 I462V and GSTM1(-). The influence of genotypes on the susceptibility of lung cancer may depend on the ages. There may be a synergetic interaction between CYP1A1 valine allele and GSTM1(-) genotypes on the elevated susceptibility of lung cancer. So do those genotypes with light smokers. Key words polymorphism; genotype; lung cancer; cytochrome P450;glutathione S-transferase Abbreviations: SCC, squamous cell carcinoma; AC, adenocarcinoma; SCLC, small cell lung cancer; LCLC, large cell lung cance
Insights into neutron star equation of state by machine learning
Due to its powerful capability and high efficiency in big data analysis,
machine learning has been applied in various fields. We construct a neural
network platform to constrain the behaviors of the equation of state of nuclear
matter with respect to the properties of nuclear matter at saturation density
and the properties of neutron stars. It is found that the neural network is
able to give reasonable predictions of parameter space and provide new hints
into the constraints of hadron interactions. As a specific example, we take the
relativistic mean field approximation in a widely accepted Walecka-type model
to illustrate the feasibility and efficiency of the platform. The results show
that the neural network can indeed estimate the parameters of the model at a
certain precision such that both the properties of nuclear matter around
saturation density and global properties of neutron stars can be saturated. The
optimization of the present modularly designed neural network and extension to
other effective models are straightforward.Comment: 12 pages, 5 figures. Comments are welcom
Associated cycles of local theta lifts of unitary characters and unitary lowest weight modules
In this paper we first construct natural filtrations on the full theta lifts
for any real reductive dual pairs. We will use these filtrations to calculate
the associated cycles and therefore the associated varieties of Harish-Chandra
modules of the indefinite orthogonal groups which are theta lifts of unitary
lowest weight modules of the metaplectic double covers of the real symplectic
groups. We will show that some of these representations are special unipotent
and satisfy a K-type formula in a conjecture of Vogan.Comment: The current version is a major revision of the first draft where we
incorporate ideas from a recent paper arXiv:1302.1031. We bypass the K-types
and asymptote calculations, and give more geometric and conceptual proof
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