7,229 research outputs found
Composite Fermions and the Fractional Quantum Hall Effect: Essential Role of the Pseudopotential
The mean field (MF) composite Fermion (CF) picture successfully predicts the
band of low lying angular momentum multiplets of fractional quantum Hall
systems for any value of the magnetic field. This success cannot be attributed
to a cancellation between Coulomb and Chern--Simons interactions between
fluctuations beyond the mean field. It results instead from the short range
behavior of the Coulomb pseudopotential in the lowest Landau level (LL). The
class of pseudopotentials for which the MFCF picture is successful can be
defined, and used to explain the success or failure of the picture in different
cases (e.g. excited LL's, charged magneto-excitons, and Laughlin quasiparticles
in a CF hierarchy picture).Comment: 4 pages, 4 figures (RevTeX+epsf); talk at EP2DS-XII
Micromechanical Analysis on the Failure Criterion of Ductile Material
AbstractBased on finite element simulation, the void growth behavior in a 3D cell model subjected to low stress triaxiality was studied. The distribution rule of stress-strain near the void was investigated, as well as the developing trend of volume of void. The analysis results indicated that it is not appropriate to regard void volume fraction as a damage parameter under the low stress triaxiality condition. Further research was carried out to verify the reliability of the fracture strain as element failure criterion by comparing the uniaxial tension simulation and experiment results. More studies were conducted to analyze the void growth under low stress triaxiality by introducing the critical equivalent plastic strain as the material failure parameter
Implicit egoism in sentencing decisions: first letter name effects with randomly assigned defendants
Implicit egotism—in particular, positive unconscious associations that individuals have with others who share their names or first initials—is a mainstay of modern psychology textbooks, but the interpretation of prior field studies has recently come under criticism for lack of adequate control, reverse causality, and ethnic heterogeneity. Using unique data from the New Orleans District Attorney’s Office on 48,988 defendants that were randomly assigned to judges from 1988-1999, we identify the causal effect of matching first initials. In contrast to positive affect, we find that judges assign 8% longer sentences on average (about two-three months) when they match on first initials. The effect is robust to controls and removal of outliers. No effect is found for second-letter matches, last-letter matches, or randomly reassigned names. The effects are somewhat larger for defendants categorized as Negroes by the New Orleans District Attorney’s Office, which could be due to sampling variation or due to behavioral biases playing a stronger role in evaluations when decision makers are nearly indifferent. The effects are also somewhat larger for judges categorized as Whites. The negative effect of sharing first initials explains 0.03% of variation. Finally, we interpret the negative behavioral effect as threatened egotism, in which individuals motivated to manage self-image (implicit egoism) create social distance from negatively- valenced targets perceived to be associated with the self
Absorption cross section in warped AdS_3 black hole revisited
We investigate the absorption cross section for minimal-coupled scalars in
the warped AdS_3 black hole. According to our calculation, the cross section
reduces to the horizon area in the low energy limit as usually expected in
contrast to what was previously found. We also calculate the greybody factor
and find that the effective temperatures for the two chiral CFT's are
consistent with that derived from the quasinormal modes. Observing the
conjectured warped AdS/CFT correspondence, we suspect that a specific sector of
the CFT operators with the desired conformal dimension could be responsible for
the peculiar thermal behaviour of the warped AdS_3 black hole.Comment: 16+1 pages, typos corrected, references and footnotes adde
From ‘Cinderella’ to ‘Beloved Princess’: The Evolution of Early Childhood Education Policy in China
published_or_final_versio
The Footprint of F-theory at the LHC
Recent work has shown that compactifications of F-theory provide a
potentially attractive phenomenological scenario. The low energy
characteristics of F-theory GUTs consist of a deformation away from a minimal
gauge mediation scenario with a high messenger scale. The soft scalar masses of
the theory are all shifted by a stringy effect which survives to low energies.
This effect can range from 0 GeV up to ~ 500 GeV. In this paper we study
potential collider signatures of F-theory GUTs, focussing in particular on ways
to distinguish this class of models from other theories with an MSSM spectrum.
To accomplish this, we have adapted the general footprint method developed
recently for distinguishing broad classes of string vacua to the specific case
of F-theory GUTs. We show that with only 5 fb^(-1) of simulated LHC data, it is
possible to distinguish many mSUGRA models and low messenger scale gauge
mediation models from F-theory GUTs. Moreover, we find that at 5 fb^(-1), the
stringy deformation away from minimal gauge mediation produces observable
consequences which can also be detected to a level of order ~ +/- 80 GeV. In
this way, it is possible to distinguish between models with a large and small
stringy deformation. At 50 fb^(-1), this improves to ~ +/- 10 GeV.Comment: 85 pages, 37 figure
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