Speaker: Dr. **Joohan Na **(KIAS)

Quantum entanglement is now considered as the main resource for quantum information and quantum computation. Distinguishing entangled states from separable ones is a fundametal problem in quantum entanglement theory, but it is so hard, especially known to be an NP-hard problem. In order to determine if a given state is separable or not, it is natural to look at the ranges of the state and its partial transposes by the PPT criterion and the range criterion. In this talk, we explain how to investigate the conditions appeared in the range criterion making use of methods in algebraic geometry and topology.

Place: Room **208**, Math Science bldg.