3,944 research outputs found
Sky location of Galactic white dwarf binaries in space-based gravitational wave detection
Quickly localizing the identified white dwarf (WD) binaries is the basic
requirement for the space-based gravitational wave (GW) detection. In fact, the
amplitude of GW signals are modulated by the periodic motion of GW detectors on
the solar orbit. The intensity of the observed signals is enhanced according to
the observation time beyond a year to enhance a high signal to noise ratio
(SNR). As data gap exists, the completeness of the data observed for a long
time depends on filling gaps in the data. Actually, in a year period, the GW
sources have a best observation orbit position of GW detectors, where the
detector response intensity of GW is maximum. Thus, the best positions, where
the direction of GW source is perpendicular to the detection arms, can be
searched for the verified GW sources of the sky map to enhance SNR too. For the
three arms response intensity of the GW signals changing more clearly with the
location of the GW sources relative to the detector, the noises and the
suppression of noise by time delay interferometer are ignored. In the four
chosen sources, the two verification WD binaries: J0806 and V407 Vul are
observed at the best orbit positions by TAIJI for the short time of 2 and 3
days respectively. The intensities of those GWs are above the values of the
TAIJI sensitivity curve, significantly. Compared with a single detector, the
network of two detectors does not significantly improve the accuracy of
location of the verification binaries. The reason of that result is that one GW
source can not be perpendicular to both detectors of TAIJI and LISA. These
results imply that the searching of GW signals and parameter estimation of GW
sources from the experimental data of the space-based mission do not ignore the
orbit positions relevant to GW sources.Comment: 22 pages, 15 figure
Two Higgs Bi-doublet Model With Spontaneous P and CP Violation and Decoupling Limit to Two Higgs Doublet Model
The two Higgs bi-doublet left-right symmetric model (2HBDM) as a simple
extension of the minimal left-right symmetric model with a single Higgs
bi-doublet is motivated to realize both spontaneous P and CP violation while
consistent with the low energy phenomenology without significant fine tuning.
By carefully investigating the Higgs potential of the model, we find that
sizable CP-violating phases are allowed after the spontaneous symmetry
breaking. The mass spectra of the extra scalars in the 2HBDM are significantly
different from the ones in the minimal left-right symmetric model. In
particular, we demonstrate in the decoupling limit when the right-handed gauge
symmetry breaking scale is much higher than the electroweak scale, the 2HBDM
decouples into general two Higgs doublet model (2HDM) with spontaneous CP
violation and has rich induced sources of CP violation. We show that in the
decoupling limit, it contains extra light Higgs bosons with masses around
electroweak scale, which can be directly searched at the ongoing LHC and future
ILC experiments.Comment: 19 pages, discussions on fine-tuning problem added. Version to appear
in Phys.Rev.
Movie101: A New Movie Understanding Benchmark
To help the visually impaired enjoy movies, automatic movie narrating systems
are expected to narrate accurate, coherent, and role-aware plots when there are
no speaking lines of actors. Existing works benchmark this challenge as a
normal video captioning task via some simplifications, such as removing role
names and evaluating narrations with ngram-based metrics, which makes it
difficult for automatic systems to meet the needs of real application
scenarios. To narrow this gap, we construct a large-scale Chinese movie
benchmark, named Movie101. Closer to real scenarios, the Movie Clip Narrating
(MCN) task in our benchmark asks models to generate role-aware narration
paragraphs for complete movie clips where no actors are speaking. External
knowledge, such as role information and movie genres, is also provided for
better movie understanding. Besides, we propose a new metric called Movie
Narration Score (MNScore) for movie narrating evaluation, which achieves the
best correlation with human evaluation. Our benchmark also supports the
Temporal Narration Grounding (TNG) task to investigate clip localization given
text descriptions. For both two tasks, our proposed methods well leverage
external knowledge and outperform carefully designed baselines. The dataset and
codes are released at https://github.com/yuezih/Movie101.Comment: Accepted to ACL 202
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