Scientific Activities
Seminars
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Seminar of Center for Theoretical Physics: | |
| Title | S-matrix Unitarity and Renormalizability |
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| Speaker | Prof. Keisuke Izumi |
| Affiliation | Nagoya University, Japan |
| Date | Tuesday, 17-09-2019 |
| Time | 10:00 AM |
| Location | Room 62, 6th floor, 2H building, 18 Hoang Quoc Viet, Cau Giay, Ha Noi |
| Abstract | We investigate the relation between the S-matrix unitarity and the renormalizability. The relation has been confirmed in many theories, such as gauge theories, Einstein gravity by analyzing the unitarity bound, which follows from the S-matrix unitarity and the norm positivity. We firstly show that the relation holds in Lifshitz-type non-relativistic theories. On the other hand, renormalizable theories with a higher derivative kinetic term do not necessarily satisfy the unitarity bound essentially because of the negative norm states. In these theories, it is not clear if the S-matrix unitarity provides a nontrivial constraint related to the renormalizability. To verify that the norm positivity is irrelevant to the relation between the S-matrix unitarity and the renormalizability, we analyze not the unitarity bound but the S-matrix unitarity itself in scalar field models with a higher derivative kinetic term. |
| Host person | Hoàng Ngọc Long |