Towards Constraining Parity-Violations in Gravity with Satellite Gradiometry

Parity violation in gravity, if existed, could have important implications, and it is meaningful to search and test the possible observational effects. Chern-Simons modified gravity serves as a natural model for gravitational parity-violations. Especially, considering extensions to Einstein-Hilbert action up to second order curvature terms, it is known that theories of gravitational parity-violation will reduce to the dynamical Chern-Simons gravity. In this letter, we outline the theoretical principles of testing the dynamical Chern-Simons gravity with orbiting gravity gradiometers, which could be naturally incorporated into future satellite gravity missions. The secular gravity gradient signals, due to the Mashhoon-Theiss (anomaly) effect, in dynamical Chern-Simons gravity are worked out, which can improve the constraint of the corresponding Chern-Simons length scale $\xi^{\frac{1}{4}}_{cs}$ obtained from such measurement scheme. For orbiting superconducting gradiometers or gradiometers with optical readout, a bound $\xi^{\frac{1}{4}}_{cs}\leq 10^6 \ km$ (or even better) could in principle be obtained, which will be at least 2 orders of magnitude stronger than the current one based on the observations from the GP-B mission and the LAGEOS I, II satellites.Comment: 15 pages, 6 figures. arXiv admin note: text overlap with arXiv:1606.0818

The Dark Side of Executive Compensation Duration: Evidence from Mergers and Acquisitions

We find that contrary to popular belief, CEOs with long compensation duration do not make better long-term investment decisions. Using a comprehensive pay duration measure, we find that acquisitions conducted by CEOs with long compensation duration receive more negative announcement returns, and experience significantly worse post-acquisition abnormal operating and stock performance, compared with deals conducted by CEOs with short compensation duration. The negative correlation between compensation duration and mergers and acquisitions (M&A) performance is driven by long-term time-vesting plans, not by performance-vesting plans. The results suggest that extending CEO pay horizons without implementing performance requirements is insufficient to improve managerial long-term investment decisions

A Comparative Study on Regularization Strategies for Embedding-based Neural Networks

This paper aims to compare different regularization strategies to address a common phenomenon, severe overfitting, in embedding-based neural networks for NLP. We chose two widely studied neural models and tasks as our testbed. We tried several frequently applied or newly proposed regularization strategies, including penalizing weights (embeddings excluded), penalizing embeddings, re-embedding words, and dropout. We also emphasized on incremental hyperparameter tuning, and combining different regularizations. The results provide a picture on tuning hyperparameters for neural NLP models.Comment: EMNLP '1

Application of Dynamic Interface Technology in Scientific Research Management System

Abstractthis paper tries to develop an Internet-based evaluation system for declaration of scientific research projects. The system, employing the integrating mode of C/S and B/S, accomplishes three functions: on-line declaration of scientific research projects, project management and on-line evaluation. The problem of dovetailing word text with database is properly solved. Furthermore, the efficiency of designation of the system is highly raised thanks to the adoption of XML store profile, DOM interface and dynamic interface technology