7,158 research outputs found
On the photofragmentation of SF: Experimental evidence for a predissociation channel
We report on the first observation of the photofragmentation dynamics of
SF. With the aid of state-of-the-art ab initio calculations on the
low-lying excited cationic states of SF performed by Lee et al. [J. Chem.
Phys. 125, 104304 (2006)], a predissociation channel of SF is evidenced
by means of resonance-enhanced multilphoton ionization spectroscopy. This work
represents a second experimental investigation on the low-lying excited
cationic states of SF. [The first one is the He I photoelectron spectrum
of SF reported by de Leeuw et al. three decades ago, see Chem. Phys. 34,
287 (1978).]Comment: 7 pages, 3 figures, submitted to JCP as a Not
Gravitating tensor monopole in a Lorentz-violating field theory
We present a solution of the coupled Einstein and rank-two antisymmetric
tensor field equations where Lorentz symmetry is spontaneously broken, and we
discuss its observational signatures. Especially, the deflection angles have
important qualitative differences between tensor and scalar monopoles. If a
monopole were to be detected, it would be discriminated whether or not to
correspond to a tensor one. This phenomenon might open up new direction in the
search of Lorentz violation with future astrophysical observations.Comment: 5 pages, 4 figure
Convexity-Concavity Indicators and Automated Trading Strategies Based on Gradient Boosted Classification Trees Models
This paper uses the visibility and invisibility algorithms to build the peak and trough indicators, providing a way to recognize the convexity, concavity and regime change of the CSI 300 Index from the April 8, 2005 to June 30, 2016. The study found that the automated trading rules discovered by the gradient boosted classification trees models derived from the peak indicator outperform that from the trough indicator. Due to the long-term bubble regime in the Chinese stock market, the technical trading rules in general have a better short term predictive ability than long term, in terms of the values of Sharpe Ratio and PnL/MD obtained from the whole out-of-sample
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