4,776 research outputs found
Learning to Generate Time-Lapse Videos Using Multi-Stage Dynamic Generative Adversarial Networks
Taking a photo outside, can we predict the immediate future, e.g., how would
the cloud move in the sky? We address this problem by presenting a generative
adversarial network (GAN) based two-stage approach to generating realistic
time-lapse videos of high resolution. Given the first frame, our model learns
to generate long-term future frames. The first stage generates videos of
realistic contents for each frame. The second stage refines the generated video
from the first stage by enforcing it to be closer to real videos with regard to
motion dynamics. To further encourage vivid motion in the final generated
video, Gram matrix is employed to model the motion more precisely. We build a
large scale time-lapse dataset, and test our approach on this new dataset.
Using our model, we are able to generate realistic videos of up to resolution for 32 frames. Quantitative and qualitative experiment results
have demonstrated the superiority of our model over the state-of-the-art
models.Comment: To appear in Proceedings of CVPR 201
Diffuse emission of TeV Neutrinos and Gamma-rays from young pulsars by Photo-meson interaction in the galaxy
It's generally believed that young and rapidly rotating pulsars are important
sites of particle's acceleration, in which protons can be accelerated to
relativistic energy above the polar cap region if the magnetic moment is
antiparallel to the spin axis(). To obtain the
galactic diffusive neutrinos and gamma-rays for TeV, firstly,we use Monte
Carlo(MC) method to generate a sample of young pulsars with ages less than
yrs in our galaxy ; secondly, the neutrinos and high-energy gamma-rays
can be produced through photomeson process with the interaction of energetic
protons and soft X-ray photons () for single pulsar, and these X-ray photons come from the
neutron star surface. The results suggest that the diffusive TeV flux of
neutrinos are lower than background flux, which indicated it is difficult to be
detected by the current neutrino telescopes.Comment: 11pages,6figures. arXiv admin note: text overlap with arXiv:0812.1845
by other author
Dynamical detection of mean-field topological phases in an interacting Chern insulator
Interactions generically have important effects on the topological quantum
phases. For a quantum anomalous Hall (QAH) insulator, the presence of
interactions can qualitatively change the topological phase diagram which,
however, is typically hard to measure in the experiment. Here we propose a
novel scheme based on quench dynamics to detect the mean-field topological
phase diagram of an interacting Chern insulator described by QAH-Hubbard model,
with nontrivial dynamical quantum physics being uncovered. We focus on the
dynamical properties of the system at a weak to intermediate Hubbard
interaction which mainly induces a ferromagnetic order under the mean-field
level. Remarkably, three characteristic times , , and are found
in the quench dynamics. The first two capture the emergence of dynamical
self-consistent particle density and dynamical topological phase transition
respectively, while the last one gives a linear scaling time on the topological
phase boundaries. A more interesting result is that
() occurs in repulsive (attractive) interaction and the Chern
number is determined by any two characteristic time scales when the system is
quenched from an initial nearly fully polarized state to the topologically
nontrivial regimes, showing a dynamical way to determine equilibrium mean-field
topological phase diagram via the time scales. Experimentally,the measurement
of is challenging while and can be directly readout by
measuring the spin polarizations of four Dirac points and the time-dependent
particle density, respectively. Our work reveals the novel interacting effects
on the topological phases and shall promote the experimental observation.Comment: 14 pages, 7 figures.Typos are corrected and References are updated.
To appear in Phys. Rev.
- β¦