>> Center for Theoretical Physics



2020 | 2019 | 2018 | 2017 | 2016 | 2015 | 2014 | 2013 | 2012 | 2011 | 2010 | >

Seminar on Theoretical and Computational Physics:
TitleS-matrix Unitarity and Renormalizability
SpeakerProf. Keisuke Izumi
AffiliationNagoya University, Japan
DateTuesday, 17-09-2019
Time10:00 AM
LocationRoom 62, 6th floor, 2H building, 18 Hoang Quoc Viet, Cau Giay, Ha Noi
AbstractWe 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 personHoàng Ngọc Long