An equal area law for holographic entanglement entropy of the AdS-RN black hole

The Anti-de Sitter-Reissner-Nordstrom (AdS-RN) black hole in the canonical ensemble undergoes a phase transition similar to the liquid-gas phase transition, i.e. the isocharges on the entropy-temperature plane develop an unstable branch when the charge is smaller than a critical value. It was later discovered that the isocharges on the entanglement entropy-temperature plane also exhibit the same van der Waals-like structure, for spherical entangling regions. In this paper, we present numerical results which sharpen this similarity between entanglement entropy and black hole entropy, by showing that both of these entropies obey Maxwell's equal area law to an accuracy of around 1 %. Moreover, we checked this for a wide range of size of the spherical entangling region, and the equal area law holds independently of the size. We also checked the equal area law for AdS-RN in 4 and 5 dimensions, so the conclusion is not specific to a particular dimension. Finally, we repeated the same procedure for a similar, van der Waals-like transition of the dyonic black hole in AdS in a mixed ensemble (fixed electric potential and fixed magnetic charge), and showed that the equal area law is not valid in this case. Thus the equal area law for entanglement entropy seems to be specific to the AdS-RN background.Comment: 17 pages, multiple figures. v4: matches published versio

Applying Theory Of Reasoned Action To Explain Inter-Firm Cooperation: Empirical Evidence From Vietnamese Enterprises

Inter-firm cooperation has received attention in recent years due to its benefit. However, little has been studied about the role of behavior intention and process by which affects cooperation behavior. From studying influencing factors which come from environmental and organizational sets, the paper will draw clear picture about the determinants of inter-firm cooperation. Based on research survey from Vietnamese enterprises, the results have confirmed the mediator role of cooperation intention which is the heart of theory of reasoned action (TRA) in making inter-firm cooperation. The results also revealed the effect of partners trust and government direction on this type of relationship. The interesting finding has stemmed from the role of relationship benefit and social influences on inter-firm behavior. The former and the later have impacted on inter-firm behavior in different ways