10,531 research outputs found
“Waste-free Cities” Construction and Carbon Emission Reduction in China: Based on the Perspective of Circular Economy
Solid waste and carbon dioxide are important elements of environmental governance. Under the background of carbon peaking and carbon neutrality goals, the research on whether and how to promote the construction of “no waste cities” and carbon emission reduction is of great significance in China. The generation of solid waste and greenhouse gases such as carbon dioxide has the same origin, which can be well coordinated to promote environmental governance
Primordial Black Holes from Sound Speed Resonance during Inflation
We report on a novel phenomenon of the resonance effect of primordial density
perturbations arisen from a sound speed parameter with an oscillatory behavior,
which can generically lead to the formation of primordial black holes in the
early Universe. For a general inflaton field, it can seed primordial density
fluctuations and their propagation is governed by a parameter of sound speed
square. Once if this parameter achieves an oscillatory feature for a while
during inflation, a significant non-perturbative resonance effect on the
inflaton field fluctuations takes place around a critical length scale, which
results in significant peaks in the primordial power spectrum. By virtue of
this robust mechanism, primordial black holes with specific mass function can
be produced with a sufficient abundance for dark matter in sizable parameter
ranges.Comment: 6 pages, 4 figures; v2: figures replotted with corrections, analysis
extended, version accepted by Phys.Rev.Let
Projective-anticipating, projective, and projective-lag synchronization of time-delayed chaotic systems on random networks
We study projective-anticipating, projective, and projective-lag
synchronization of time-delayed chaotic systems on random networks. We relax
some limitations of previous work, where projective-anticipating and
projective-lag synchronization can be achieved only on two coupled chaotic
systems. In this paper, we can realize projective-anticipating and
projective-lag synchronization on complex dynamical networks composed by a
large number of interconnected components. At the same time, although previous
work studied projective synchronization on complex dynamical networks, the
dynamics of the nodes are coupled partially linear chaotic systems. In this
paper, the dynamics of the nodes of the complex networks are time-delayed
chaotic systems without the limitation of the partial-linearity. Based on the
Lyapunov stability theory, we suggest a generic method to achieve the
projective-anticipating, projective, and projective-lag synchronization of
time-delayed chaotic systems on random dynamical networks and find both the
existence and sufficient stability conditions. The validity of the proposed
method is demonstrated and verified by examining specific examples using Ikeda
and Mackey-Glass systems on Erdos-Renyi networks.Comment: 14 pages, 6 figure
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