On the photofragmentation of SF2+_2^+: Experimental evidence for a predissociation channel

We report on the first observation of the photofragmentation dynamics of SF$_2^+$. With the aid of state-of-the-art ab initio calculations on the low-lying excited cationic states of SF$_2^+$ performed by Lee et al. [J. Chem. Phys. 125, 104304 (2006)], a predissociation channel of SF$_2^+$ 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$_2^+$. [The first one is the He I photoelectron spectrum of SF$_2^+$ 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