1,554 research outputs found
Quark-lepton complementarity revisited
We reexamine the quark-lepton complementarity (QLC) in nine angle-phase
parametrizations with the latest result of a large lepton mixing angle
from the T2K, MINOS and Double Chooz experiments. We find that
there are still two QLC relations satisfied in P1, P4 and P6 parametrizations,
whereas only one QLC relation holds in P2, P3, P5 and P9 parametrizations
separately. We also work out the corresponding reparametrization-invariant
forms of the QLC relations and check the resulting expressions with the
experimental data. The results can be viewed as a check of the validity of the
QLC relations, as well as a new perspective into the issue of seeking for the
connection between quarks and leptons.Comment: 5 Latex pages, 2 tables. Final version for publication in PR
Constraining the Mass of the Photon with Gamma-Ray Bursts
One of the cornerstones of modern physics is Einstein's special relativity,
with its constant speed of light and zero photon mass assumptions. Constraint
on the rest mass m_{\gamma} of photons is a fundamental way to test Einstein's
theory, as well as other essential electromagnetic and particle theories. Since
non-zero photon mass can give rise to frequency-(or energy-) dependent
dispersions, measuring the time delay of photons with different frequencies
emitted from explosive astrophysical events is an important and
model-independent method to put such a constraint. The cosmological gamma-ray
bursts (GRBs), with short time scales, high redshifts as well as broadband
prompt and afterglow emissions, provide an ideal testbed for m_{\gamma}
constraints. In this paper we calculate the upper limits of the photon mass
with GRB early time radio afterglow observations as well as multi-band radio
peaks, thus improve the results of Schaefer (1999) by nearly half an order of
magnitude.Comment: 25 pages, 2 tables, Accepted by Journal of High Energy Astrophysic
Lifshitz Scaling Effects on Holographic Superconductors
Via numerical and analytical methods, the effects of the Lifshitz dynamical
exponent on holographic superconductors are studied in some detail,
including wave and wave models. Working in the probe limit, we find
that the behaviors of holographic models indeed depend on concrete value of
. We obtain the condensation and conductivity in both Lifshitz black hole
and soliton backgrounds with general . For both wave and wave models
in the black hole backgrounds, as increases, the phase transition becomes
more difficult and the growth of conductivity is suppressed. For the Lifshitz
soliton backgrounds, when increases (), the critical chemical
potential decreases in the wave cases but increases in the wave cases.
For wave models in both Lifshitz black hole and soliton backgrounds, the
anisotropy between the AC conductivity in different spatial directions is
suppressed when increases. The analytical results uphold the numerical
results.Comment: Typos corrected; Footnote added; References added; To be published in
Nuclear Physics
Five-dimensional generalized gravity with curvature-matter coupling
The generalized gravity with curvature-matter coupling in
five-dimensional (5D) spacetime can be established by assuming a
hypersurface-orthogonal spacelike Killing vector field of 5D spacetime, and it
can be reduced to the 4D formulism of FRW universe. This theory is quite
general and can give the corresponding results to the Einstein gravity,
gravity with both no-coupling and non-minimal coupling in 5D spacetime as
special cases, that is, we would give the some new results besides previous
ones given by Ref.\cite{60}. Furthermore, in order to get some insight into the
effects of this theory on the 4D spacetime, by considering a specific type of
models with and , we not
only discuss the constraints on the model parameters , , but also
illustrate the evolutionary trajectories of the scale factor , the
deceleration parameter and the scalar field , in
the reduced 4D spacetime. The research results show that this type of
gravity models given by us could explain the current accelerated expansion of
our universe without introducing dark energy.Comment: arXiv admin note: text overlap with arXiv:0912.4581,
arXiv:gr-qc/0411066 by other author
Masking: A New Perspective of Noisy Supervision
It is important to learn various types of classifiers given training data
with noisy labels. Noisy labels, in the most popular noise model hitherto, are
corrupted from ground-truth labels by an unknown noise transition matrix. Thus,
by estimating this matrix, classifiers can escape from overfitting those noisy
labels. However, such estimation is practically difficult, due to either the
indirect nature of two-step approaches, or not big enough data to afford
end-to-end approaches. In this paper, we propose a human-assisted approach
called Masking that conveys human cognition of invalid class transitions and
naturally speculates the structure of the noise transition matrix. To this end,
we derive a structure-aware probabilistic model incorporating a structure
prior, and solve the challenges from structure extraction and structure
alignment. Thanks to Masking, we only estimate unmasked noise transition
probabilities and the burden of estimation is tremendously reduced. We conduct
extensive experiments on CIFAR-10 and CIFAR-100 with three noise structures as
well as the industrial-level Clothing1M with agnostic noise structure, and the
results show that Masking can improve the robustness of classifiers
significantly.Comment: NIPS 2018 camera-ready versio
Lifshitz effects on holographic -wave superfluid
In the probe limit, we numerically build a holographic -wave superfluid
model in the four-dimensional Lifshitz black hole coupled to a Maxwell-complex
vector field. We observe the rich phase structure and find that the Lifshitz
dynamical exponent contributes evidently to the effective mass of the
matter field and dimension of the gravitational background. Concretely, we
obtain the Cave of Winds appeared only in the five-dimensional anti-de
Sitter~(AdS) spacetime, and the increasing hinders not only the condensate
but also the appearance of the first-order phase transition. Furthermore, our
results agree with the Ginzburg-Landau results near the critical temperature.
In addition, the previous AdS superfluid model is generalized to the Lifshitz
spacetime.Comment: 14 pages,5 figures, and 1 table, accepted by Phys. Lett.
Multi-Dimensional Recommendation Scheme for Social Networks Considering a User Relationship Strength Perspective
Developing a computational method based on user relationship strength for multi-dimensional recommendation is a significant challenge. The traditional recommendation methods have relatively low accuracy because they lack considering information from the perspective of user relationship strength into the recommendation algorithm. User relationship strength reflects the degree of closeness between two users, which can make the recommendation system more efficient between users in pairs. This paper proposes a multi-dimensional comprehensive recommendation method based on user relationship strength. We take three main factors into consideration, including the strength of user relationship, the similarity of entities, and the degree of user interest. First, we introduce a novel method to generate a user candidate set and an entity candidate set by calculating the relationship strength between two users and the similarity between two entities. Then, the algorithm will calculate the user interest degree of each user in the user candidate set to each entity in the entity candidate set, if the user interest degree is larger than or equal to a threshold, this particular entity will be recommended to this user. The performance of the proposed method was verified based on the real-world social network dataset and the e-commerce website dataset, and the experimental result suggests that this method can improve the recommendation accuracy
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