Abstract
The ΛCDM model provides the standard description of our Universe, yet the origin of the cosmological constant remains unresolved. The speaker will show that in a class of anomaly-free six-dimensional supergravity theories with local R-symmetry, one can naturally obtain classical four- and six-dimensional vacuum solutions with a positive cosmological constant. This mechanism does not rely on nonperturbative effects or higher-order corrections, which are typically required in conventional string-theoretic constructions, and thus provides a new realization of de Sitter vacua within the low-energy effective theory of quantum gravity.
Dr. Yi Pang received his PhD from the Institute of Theoretical Physics, Chinese Academy of Science in 2011. He subsequently held positions as a Research Assistant at Texas A&M University, a Humboldt Fellow at the Max Planck Institute for Gravitational Physics, and a Royal Society Newton Fellow affiliated with the University of Oxford. In 2020, he joined Tianjin University as a Professor.