Seminarium Fizyki Materii Skondensowanej
sala 1.02, ul. Pasteura 5
2018-12-07 (12:15) 
Jacek Wojtkiewicz (KMMF UW)
On the non-existence of Bose-Einstein condensation in d=1 and 2 Bose-Hubbard model
It is argued that there is no Bose-Einstein condensation in d=1 and 2 Bose-Hubbard model. The argument is based on Bogolyubov-type inequality. The situation is more involved than in the fermionic case, as unbounded operators are present and they have to be treated carefully. The exposition is based on joint work with W. Pusz and P. Stachura.