5,231 research outputs found
Dynamical symmetries of the Klein-Gordon equation
The dynamical symmetries of the two-dimensional Klein-Gordon equations with
equal scalar and vector potentials (ESVP) are studied. The dynamical symmetries
are considered in the plane and the sphere respectively. The generators of the
SO(3) group corresponding to the Coulomb potential, and the SU(2) group
corresponding to the harmonic oscillator potential are derived. Moreover, the
generators in the sphere construct the Higgs algebra. With the help of the
Casimir operators, the energy levels of the Klein-Gordon systems are yielded
naturally.Comment: 4
Impacts of gravitational-wave standard siren observation of the Einstein Telescope on weighing neutrinos in cosmology
We investigate the impacts of the gravitational-wave (GW) standard siren
observation of the Einstein Telescope (ET) on constraining the total neutrino
mass. We simulate 1000 GW events that would be observed by the ET in its
10-year observation by taking the standard CDM cosmology as a fiducial
model. We combine the simulated GW data with other cosmological observations
including cosmic microwave background (CMB), baryon acoustic oscillations
(BAO), and type Ia supernovae (SN). We consider three mass hierarchy cases for
the neutrino mass, i.e., normal hierarchy (NH), inverted hierarchy (IH), and
degenerate hierarchy (DH). Using Planck+BAO+SN, we obtain eV
for the NH case, eV for the IH case, and
eV for the DH case. After considering the GW data, i.e., using
Planck+BAO+SN+GW, the constraint results become eV for the
NH case, eV for the IH case, and eV for
the DH case. We find that the GW data can help reduce the upper limits of by 13.7%, 7.5%, and 10.3% for the NH, IH, and DH cases, respectively. In
addition, we find that the GW data can also help break the degeneracies between
and other parameters. We show that the GW data of the ET could
greatly improve the constraint accuracies of cosmological parameters.Comment: 8 pages, 4 figure
Forward Attention in Sequence-to-sequence Acoustic Modelling for Speech Synthesis
This paper proposes a forward attention method for the sequenceto- sequence
acoustic modeling of speech synthesis. This method is motivated by the nature
of the monotonic alignment from phone sequences to acoustic sequences. Only the
alignment paths that satisfy the monotonic condition are taken into
consideration at each decoder timestep. The modified attention probabilities at
each timestep are computed recursively using a forward algorithm. A transition
agent for forward attention is further proposed, which helps the attention
mechanism to make decisions whether to move forward or stay at each decoder
timestep. Experimental results show that the proposed forward attention method
achieves faster convergence speed and higher stability than the baseline
attention method. Besides, the method of forward attention with transition
agent can also help improve the naturalness of synthetic speech and control the
speed of synthetic speech effectively.Comment: 5 pages, 3 figures, 2 tables. Published in IEEE International
Conference on Acoustics, Speech and Signal Processing 2018 (ICASSP2018
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