报告题目：Thermodynamic phase structure of complex SYK models: Hermitian and non-Hermitian Aspects

报  告 人：葛先辉 教授、上海大学

研究方向：引力理论

报告时间：2023年4月3日（星期一）下午16:00

报告地点：量子楼410

报告摘要：

In this talk, I will discuss the thermodynamic phase structure of complex SYK models from the perspective of Hermitian and non-Hermitian point of view. For Hermitian single-sided complex SYK model, it exhibits a first-order phase transition terminating at the critical point, while the charged black hole in JT gravity shows a clear van der Waals-Maxwell like phase structure. In the absence of charge, the corresponding neutral black hole still has the Hawking-Page phase transition. For non-Hermitian two-sided SYK model, we find that this system describes traversable wormhole in the low temperature with negative null energy. A first order phase transition between gapped phase (traversable wormhole) and gapless SYK phase (black hole) can be obtained for finite non-Hermiticity but different couplings. Compared with Hermitian case, the influence of the non-Hermitian parameter is only seen in Green's functions and ground states by the symmetry breaking of left and right sides. The energy spectrum, the degree of entanglement for ground states and the thermodynamic phase structure are not influenced by the non-Hermitian parameter.

报告人简介：

葛先辉，上海大学理学院物理系教授，系主任；2006年中科院上海天文台获博士学位，2006年至2008年，韩国亚太物理中心从事博士后研究；2008年至今，上海大学物理系工作。2016-2017年，美国加州大学圣地亚哥分校 高级访问学者。曾获上海市科技启明星计划资助，主持多项国家自然科学基金项目。主要研究领域：引力论与宇宙论、AdS/CFT对应、引力与规范场论对偶，黑洞物理、强耦合量子多体理论、类比引力理论。在JHEP,PRD等国内外主要学术刊物上发表论文80余篇。