2,636 research outputs found
A three-loop radiative neutrino mass model with dark matter
We present a model that generates small neutrino masses at three-loop level
due to the existence of Majorana fermionic dark matter, which is stabilized by
a Z2 symmetry. The model predicts that the lightest neutrino is massless. We
show a prototypical parameter choice allowed by relevant experimental data,
which favors the case of normal neutrino mass spectrum and the dark matter with
m \sim 50-135 GeV and a sizable Yukawa coupling. It means that new particles
can be searched for in future e+e- collisions.Comment: 7 pages, 3 figure
Representation Learning for Scale-free Networks
Network embedding aims to learn the low-dimensional representations of
vertexes in a network, while structure and inherent properties of the network
is preserved. Existing network embedding works primarily focus on preserving
the microscopic structure, such as the first- and second-order proximity of
vertexes, while the macroscopic scale-free property is largely ignored.
Scale-free property depicts the fact that vertex degrees follow a heavy-tailed
distribution (i.e., only a few vertexes have high degrees) and is a critical
property of real-world networks, such as social networks. In this paper, we
study the problem of learning representations for scale-free networks. We first
theoretically analyze the difficulty of embedding and reconstructing a
scale-free network in the Euclidean space, by converting our problem to the
sphere packing problem. Then, we propose the "degree penalty" principle for
designing scale-free property preserving network embedding algorithm: punishing
the proximity between high-degree vertexes. We introduce two implementations of
our principle by utilizing the spectral techniques and a skip-gram model
respectively. Extensive experiments on six datasets show that our algorithms
are able to not only reconstruct heavy-tailed distributed degree distribution,
but also outperform state-of-the-art embedding models in various network mining
tasks, such as vertex classification and link prediction.Comment: 8 figures; accepted by AAAI 201
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