2,677 research outputs found
Non-Abelian Chiral Spin Liquid on the Kagome Lattice
We study spin liquid states on the kagome lattice constructed by
Gutzwiller-projected superconductors. We show that the obtained spin
liquids are either non-Abelian or Abelian topological phases, depending on the
topology of the fermionic mean-field state. By calculating the modular matrices
and , we confirm that projected topological superconductors are
non-Abelian chiral spin liquid (NACSL). The chiral central charge and the spin
Hall conductance we obtained agree very well with the (or,
equivalently, ) field theory predictions. We propose a local
Hamiltonian which may stabilize the NACSL. From a variational study we observe
a topological phase transition from the NACSL to the Abelian spin liquid.Comment: 12 pages, 7 figures, 1 tabl
Identifying online user reputation of user–object bipartite networks
Identifying online user reputation based on the rating information of the user–object bipartite networks is important for understanding online user collective behaviors. Based on the Bayesian analysis, we present a parameter-free algorithm for ranking online user reputation, where the user reputation is calculated based on the probability that their ratings are consistent with the main part of all user opinions. The experimental results show that the AUC values of the presented algorithm could reach 0.8929 and 0.8483 for the MovieLens and Netflix data sets, respectively, which is better than the results generated by the CR and IARR methods. Furthermore, the experimental results for different user groups indicate that the presented algorithm outperforms the iterative ranking methods in both ranking accuracy and computation complexity. Moreover, the results for the synthetic networks show that the computation complexity of the presented algorithm is a linear function of the network size, which suggests that the presented algorithm is very effective and efficient for the large scale dynamic online systems
Limiting Superluminal Neutrino Velocity and Lorentz Invariance Violation by Neutrino Emission from the Blazar TXS 0506+056
The detection of high-energy neutrino coincident with the blazar TXS 0506+056
provides a unique opportunity to test Lorentz invariance violation (LIV) in the
neutrino sector. Thanks to the precisely measured redshift, i.e., ,
the comoving distance of the neutrino source is determined. In this work, we
obtain and discuss the constraints on the superluminal neutrino velocity
and the LIV by considering the energy loss of superluminal
neutrino during propagation. Given superluminal electron velocity (), a very stringent constraint on superluminal neutrino velocity can be
reached, i.e., , corresponding to the
quantum gravity (QG) scale
and for linear (quadratic)
LIV, which are orders of magnitude tighter for linear LIV and orders tighter for quadratic LIV compared to the time-of-flight constraint
from MeV neutrinos of SN 1987A. While given the subluminal electron velocity, a
weaker constraint on the superluminal neutrino velocity is obtained, i.e.,
, which is consistent with the
conclusions of previous works. We also study the neutrino detection probability
due to the distortion of neutrino spectral shape during propagation, which
gives slightly weaker constraints than above by a factor of .Comment: 4 pages, 1 table, accepted by Phys. Rev.
Spatial multi-objective land use optimization toward livability based on boundary-based genetic algorithm: A case study in Singapore
Singapore Management University; Ministry of Education, Singapore under its Academic Research Funding Tier
Astragalus Polysaccharides Lowers Plasma Cholesterol through Mechanisms Distinct from Statins
To determine the efficacy and underlying mechanism of Astragalus polysaccharides (APS) on plasma lipids in hypercholesterolemia hamsters. The effect of APS (0.25g/kg/d) on plasma and liver lipids, fecal bile acids and neutral sterol, cholesterol absorption and synthesis, HMG-CoA reductase activity, and gene and protein expressions in the liver and small intestine was investigated in twenty-four hypercholesterolemia hamsters. Treatment periods lasted for three months. APS significantly lowered plasma total cholesterol by 45.8%, triglycerides by 30%, and low-density lipoprotein-cholesterol by 47.4%, comparable to simvastatin. Further examinations revealed that APS reduced total cholesterol and triglycerides in the liver, increased fecal bile acid and neutral sterol excretion, inhibited cholesterol absorption, and by contrast, increased hepatic cholesterol synthesis and HMG-CoA reductase activity. Plasma total cholesterol or low-density lipoprotein-cholesterol levels were significantly correlated with cholesterol absorption rates. APS up-regulated cholesterol-7α-hydroxylase and LDL-receptor gene expressions. These new findings identify APS as a potential natural cholesterol lowering agent, working through mechanisms distinct from statins
Evolution properties of the community members for dynamic networks
The collective behaviors of community members for dynamic social networks are significant for understanding evolution features of communities. In this Letter, we empirically investigate the evolution properties of the new community members for dynamic networks. Firstly, we separate data sets into different slices, and analyze the statistical properties of new members as well as communities they joined in for these data sets. Then we introduce a parameter φ to describe community evolution between different slices and investigate the dynamic community properties of the new community members. The empirical analyses for the Facebook, APS, Enron and Wiki data sets indicate that both the number of new members and joint communities increase, the ratio declines rapidly and then becomes stable over time, and most of the new members will join in the small size communities that is s≤10s≤10. Furthermore, the proportion of new members in existed communities decreases firstly and then becomes stable and relatively small for these data sets. Our work may be helpful for deeply understanding the evolution properties of community members for social networks
- …