5,485 research outputs found
Communication with SIMP dark mesons via Z'-portal
We consider a consistent extension of the SIMP models with dark mesons by
including a dark U(1)_D gauge symmetry. Dark matter density is determined by a
thermal freeze-out of the self-annihilation process, thanks to the
Wess-Zumino-Witten term. In the presence of a gauge kinetic mixing between the
dark photon and the SM hypercharge gauge boson, dark mesons can undergo a
sufficient scattering off the Standard Model particles and keep in kinetic
equilibrium until freeze-out in this SIMP scenario. Taking the
SU(N_f)xSU(N_f)/SU(N_f) flavor symmetry under the SU(N_c) confining group, we
show how much complementary the SIMP constraints on the parameters of the dark
photon are for current experimental searches for dark photon.Comment: 16 pages, 6 figures, To appear in Phys. Lett.
SIMP dark matter and its cosmic abundances
We give a review on the thermal average of the annihilation cross-sections
for and general higher-order processes. Thermal average of
higher order annihilations highly depend on the velocity of dark matter,
especially, for the case with resonance poles. We show such examples for scalar
dark matter in gauged models.Comment: 5 pages, 2 figures, Prepared for the proceedings of the 13th
International Conference on Gravitation, 3-7 July 201
Cosmic abundances of SIMP dark matter
Thermal production of light dark matter with sub-GeV scale mass can be
attributed to self-annihilation processes. We consider the
thermal average for annihilation cross sections of dark matter at and general higher-order interactions. A correct thermal average for initial
dark matter particles is important, in particular, for annihilation cross
sections with overall velocity dependence and/or resonance poles. We apply our
general results to benchmark models for SIMP dark matter and discuss the
effects of the resonance pole in determining the relic density.Comment: 21 pages, 6 figures, Version to appear in Journal of High Energy
Physic
Self-Supervised Curriculum Generation for Autonomous Reinforcement Learning without Task-Specific Knowledge
A significant bottleneck in applying current reinforcement learning
algorithms to real-world scenarios is the need to reset the environment between
every episode. This reset process demands substantial human intervention,
making it difficult for the agent to learn continuously and autonomously.
Several recent works have introduced autonomous reinforcement learning (ARL)
algorithms that generate curricula for jointly training reset and forward
policies. While their curricula can reduce the number of required manual resets
by taking into account the agent's learning progress, they rely on
task-specific knowledge, such as predefined initial states or reset reward
functions. In this paper, we propose a novel ARL algorithm that can generate a
curriculum adaptive to the agent's learning progress without task-specific
knowledge. Our curriculum empowers the agent to autonomously reset to diverse
and informative initial states. To achieve this, we introduce a success
discriminator that estimates the success probability from each initial state
when the agent follows the forward policy. The success discriminator is trained
with relabeled transitions in a self-supervised manner. Our experimental
results demonstrate that our ARL algorithm can generate an adaptive curriculum
and enable the agent to efficiently bootstrap to solve sparse-reward maze
navigation tasks, outperforming baselines with significantly fewer manual
resets.Comment: 8 pages, 5 figure
Issues and Trends in Cross-border E-commerce in Korea
Consumers purchase cross-border e-commerce products directly from overseas online shopping malls. An increase in the popularity of cross-border e-commerce means that smart consumption trends revolutionized the consumption process. The scale of cross-border e-commerce in Korea reached a record high in 2017. Existing literature suggests that the sharp increase is due to price, product diversity, efficient shipping, expansion of duty-free range and hedonic motivation. A semantic network analysis revealed three main clusters in relationships between cross-border e-commerce research subjects: consumer, country and process
CMB Spectral -Distortion of Multiple Inflation Scenario
In multiple inflation scenario having two inflations with an intermediate
matter-dominated phase, the power spectrum is estimated to be enhanced on
scales smaller than the horizon size at the beginning of the second inflation,
. We require to make sure that
the enhanced power spectrum is consistent with large scale observation of
cosmic microwave background (CMB). We consider the CMB spectral distortions
generated by the dissipation of acoustic waves to constrain the power spectrum.
The -distortion value can be times larger than the expectation of the
standard CDM model () for , while the
-distortion is hardly affected by the enhancement of the power spectrum.Comment: 16 pages, 5 figure
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