4,049 research outputs found
A Monte-Carlo simulation of the equilibrium beam polarization in ultra-high energy electron (positron) storage rings
With the recently emerging global interest in building a next generation of
circular electron-positron colliders to study the properties of the Higgs
boson, and other important topics in particle physics at ultra-high beam
energies, it is also important to pursue the possibility of implementing
polarized beams at this energy scale. It is therefore necessary to set up
simulation tools to evaluate the beam polarization at these ultra-high beam
energies. In this paper, a Monte-Carlo simulation of the equilibrium beam
polarization based on the Polymorphic Tracking Code(PTC) (Schmidt et al., 2002
[1]) is described. The simulations are for a model storage ring with parameters
similar to those of proposed circular colliders in this energy range, and they
are compared with the suggestion (Derbenev et al., 1978 [2]) that there are
different regimes for the spin dynamics underlying the polarization of a beam
in the presence of synchrotron radiation at ultra-high beam energies. In
particular, it has been suggested that the so-called "correlated" crossing of
spin resonances during synchrotron oscillations at current energies, evolves
into "uncorrelated" crossing of spin resonances at ultra-high energies.Comment: submitted to and accepted by Nucl. Instrum. Meth.
Empirical investigation of nonlinear asset pricing kernel with human capital and housing wealth
In a traditional framework, asset returns are captured by simple linear asset pricing models. They include Capital Asset Pricing Model (CAPM) and Fama-French threefactor
model. However, the empirical study shows that the asset returns are fat tailed, that cannot be accurately predicted by normal distribution. Kurtosis and skewness should be considered when pricing those non-normal assets. Various literatures can be found focused on this topic. Bansal and Viswanathan (1993) and Chapman (1997) developed nonparametric model. They find that the nonparametric models perform better in explaining expected returns. Most recently, nonlinear asset pricing models developed by Dittmar (2002) shows more significantly improvements in return estimation, compared to the linear single and linear multi-factor models.
In this study, I focus on an asset-pricing model of higher order risk factors and use polynomial pricing kernel to generate the empirical performance of a nonlinear model. This is an extension to both Bansal and Dittmar’s work, by extending the definition of the total wealth including human capital and housing wealth. This research work is novel and especially important to understand asset price behavior after year 2007, the credit crisis. Housing price growth rate is a very critical indicator for long-term investment, reflecting consumer confidence on the long-term global economy. It can be used to estimate the turning point for the recent economic down turn. In addition, since the credit crisis 2008 is triggered by liquidity shortage in
banking systems, the level of housing price has direct impact on the balance sheet of those banking sectors. The higher the house price, the more willingness banks have to
release the credit to the market. The housing wealth factor can be used to estimate when the credit crunch will disappear and global economy gets fully recovered.
In this study, the risk factors that represent the aggregate wealth in the economic are tested. The best possible proxy of return on the total wealth is discussed. The thesis can be divided into 2 parts. In the first part of my thesis, a higher order moment model to explain the asset price behaviour is developed. Similar to the work presented by Dittmar (2002), pricing kernel is approximated using Taylor Series expansion and Hansen-Jagannathan (1997) weighting matrix. The time-varying coefficients with
respected sign of coefficients are estimated. Housing factor is added to extend the model, as we believe that housing plays an important role in the return on aggregate
wealth. In the second part of my thesis, I test models in three time periods. They include Dittmar’s period from 1963 to 1995, the full sample period from 1963 to 2009 and recent period from 1996 to 2009.
Our results confirm that nonlinear models outperform than linear models in explaining the cross section of returns. The higher order risk factors give the magnitude improvement in model fitting. This is consistent with the result given by Dittmar (2002). Moreover, my results conclude that the models with the housing wealth included performs significantly better than the models with human capital only
A Comparative Study of Syntactic Hypotaxis and Parataxis in English and Chinese From the Aesthetic Perspective of Classical Painting
Parataxis is the main grammatical feature of Chinese sentences while hypotaxis is the main grammatical feature of English. Similarly, Chinese classical paintings stress on the psychological harmony of subject-object unity and Western classical paintings on extrinsic form. It is found that the aesthetic thinking of classical painting is reflected in English and Chinese syntactic structure
Fermionic phase transition induced by the effective impurity in holography
We investigate the holographic fermionic phase transition induced by the
effective impurity in holography, which is introduced by massless scalar fields
in Einstein-Maxwell-massless scalar gravity. We obtain a phase diagram in
plane separating the Fermi liquid phase and the non-Fermi liquid
phase.Comment: 17 pages, 9 figure
Infinitely many solutions for elliptic problems in involving the -Laplacian
We consider the -Laplacian equations in . The potential function does not satisfy the coercive condition. We obtain the existence of infinitely many solutions of the equations, improving a recent result of Duan--Huang [L. Duan, L. H. Huang, Electron. J. Qual. Theory Differ. Equ. 2014, No. 28, 1--13]
RecQ helicase enhances homologous recombination in plants
AbstractRecQ helicase is a key component in the RecF pathway of Escherichia coli for initiation of homologous recombination. Here, we demonstrate that transient expression of RecQ gene in rice embryogenic cell increases the homologous recombination efficiency as much as 4-fold. Further experiments reveal that this effect is influenced by the RecQ dosage. Stable expression of RecQ in rice dramatically increases the homologous recombination events 20- to 40-fold in leaf tissue from different transgenic lines. This is the first evidence indicating that overexpression of RecQ gene can stimulate homologous recombination in plants
Luttinger-volume violating Fermi liquid in the pseudogap phase of the cuprate superconductors
Based on the NMR measurements on BiSrLaCuO
(La-Bi2201) in strong magnetic fields, we identify the non-superconducting
pseudogap phase in the cuprates as a Luttinger-volume violating Fermi liquid
(LvvFL). This state is a zero temperature quantum liquid that does not break
translational symmetry, and yet, the Fermi surface encloses a volume smaller
than the large one given by the Luttinger theorem. The particle number enclosed
by the small Fermi surface in the LvvFL equals the doping level , not the
total electron number . Both the phase string theory and the dopon
theory are introduced to describe the LvvFL. For the dopon theory, we can
obtain a semi-quantitative agreement with the NMR experiments.Comment: The final version in PR
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