Non-Relativistic Limit of Dirac Equations in Gravitational Field and Quantum Effects of Gravity

Based on unified theory of electromagnetic interactions and gravitational interactions, the non-relativistic limit of the equation of motion of a charged Dirac particle in gravitational field is studied. From the Schrodinger equation obtained from this non-relativistic limit, we could see that the classical Newtonian gravitational potential appears as a part of the potential in the Schrodinger equation, which can explain the gravitational phase effects found in COW experiments. And because of this Newtonian gravitational potential, a quantum particle in earth's gravitational field may form a gravitationally bound quantized state, which had already been detected in experiments. Three different kinds of phase effects related to gravitational interactions are discussed in this paper, and these phase effects should be observable in some astrophysical processes. Besides, there exists direct coupling between gravitomagnetic field and quantum spin, radiation caused by this coupling can be used to directly determine the gravitomagnetic field on the surface of a star.Comment: 12 pages, no figur

Holographic Inequalities and Entanglement of Purification

We study the conjectured holographic duality between entanglement of purification and the entanglement wedge cross-section. We generalize both quantities and prove several information theoretic inequalities involving them. These include upper bounds on conditional mutual information and tripartite information, as well as a lower bound for tripartite information. These inequalities are proven both holographically and for general quantum states. In addition, we use the cyclic entropy inequalities to derive a new holographic inequality for the entanglement wedge cross-section, and provide numerical evidence that the corresponding inequality for the entanglement of purification may be true in general. Finally, we use intuition from bit threads to extend the conjecture to holographic duals of suboptimal purifications.Comment: 17 pages, 4 figures, 1 table. v2: added clarification and fixed typ

Self-Employment of Rural-to-Urban Migrants in China

This paper focuses on the determinants of self-employment among rural to urban migrants in China. Two self-selection mechanisms are analysed: the first relates to the manner in which migrants choose self-employment or paid work based on the potential gains from either type of employment; the second takes into account that the determinants of the migration decision can be correlated with employment choices. Using data from the 2008 Rural-Urban Migration in China and Indonesia (RUMiCI) survey, a selection model with endogenous switching is estimated. Earnings estimates are then used to derive the wage differential, which in turn is used to model the employment choice. The procedure is extended to account for migration selectivity and to compare individuals with different migration background and employment histories. The results indicate that self-employed individuals are positively selected with respect to their unobserved characteristics. Furthermore, the wage differential is found to be an important driver of the self-employment choice.self-employment, rural to urban migration, selection bias magnets, wages, European Union