About Guangshan Tian’s work
Guangshan Tian held a Croucher Visitorship at Hong Kong Baptist University from January to June 1998. At the time, Tian was based at Peking University.
Biography
Guangshan Tian entered the Department of Physics of Peking University in 1978, and went to the Department of Physics of Princeton University in 1981. He received a PhD in mathematical physics in 1986 and after that he went to the Department of Mathematics of Texas State University at Austin for postdoctoral research. In 1989, he worked as a postdoctoral fellow in the Department of Physics of Peking University. Tian has worked on some qualitative results of strongly correlated electronic systems.
As a supplement to the Mermin-Wagner theorem, a sufficient condition for the non-existence of a certain type of long-range order is established when the temperature is zero, and this result is further extended to a sufficient condition for the coexistence of two types of long-range order. In the case that the number of electrons is odd, the spin reflection positivity method is popularized, so as to establish a universal relationship between the charge energy gap and the spin energy gap in the strongly correlated electronic system.