23,896 research outputs found
Dark energy imprints on the kinematic Sunyaev-Zel'dovich signal
We investigate the imprint of dark energy on the kinetic Sunyaev-Zel'dovich
(kSZ) angular power spectrum on scales of to , and find that
the kSZ signal is sensitive to the dark energy parameter. For example, varying
the constant by 20\% around results in a change on the
kSZ spectrum; changing the dark energy dynamics parametrized by by
, a 30\% change on the kSZ spectrum is expected. We discuss the
observational aspects and develop a fitting formula for the kSZ power spectrum.
Finally, we discuss how the precise modeling of the post-reionization signal
would help the constraints on patchy reionization signal, which is crucial for
measuring the duration of reionization.Comment: 12 pages, 9 figures, 2 table
Effect of sea quarks on the single-spin asymmetries in polarized pp collisions at RHIC
We calculate the single-spin asymmetries of
bosons produced in polarized pp collisions with the valence part of the up and
down quark helicity distributions modeled by the light-cone
quark-spectator-diquark model while the sea part helicity distributions of the
up and down quarks treated as parametrization. Comparing our results with those
from experimental data at RHIC, we find that the helicity distributions of sea
quarks play an important role in the determination of the shapes of
. It is shown that is sensitive to , while to intuitively. The experimental
data of the polarized structure functions and the sum of helicities are also
important to constrain the sizes of quark helicity distributions both for the
sea part and the valence part of the nucleon.Comment: 19 latex pages, 5 figures, final version for publicatio
Generating Text Sequence Images for Recognition
Recently, methods based on deep learning have dominated the field of text
recognition. With a large number of training data, most of them can achieve the
state-of-the-art performances. However, it is hard to harvest and label
sufficient text sequence images from the real scenes. To mitigate this issue,
several methods to synthesize text sequence images were proposed, yet they
usually need complicated preceding or follow-up steps. In this work, we present
a method which is able to generate infinite training data without any auxiliary
pre/post-process. We tackle the generation task as an image-to-image
translation one and utilize conditional adversarial networks to produce
realistic text sequence images in the light of the semantic ones. Some
evaluation metrics are involved to assess our method and the results
demonstrate that the caliber of the data is satisfactory. The code and dataset
will be publicly available soon
Cosmological Implications of 5-dimensional Brans-Dicke Theory
The five dimensional Brans-Dicke theory naturally provides two scalar fields
by the Killing reduction mechanism. These two scalar fields could account for
the accelerated expansion of the universe. We test this model and constrain its
parameter by using the type Ia supernova (SN Ia) data. We find that the best
fit value of the 5-dimensional Brans-Dicke coupling contant is .
This result is also consistent with other observations such as the baryon
acoustic oscillation (BAO).Comment: 5 pages, 4 figures, PLB accepte
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