Seminar of Research Training Group
Spin memory effect and charges of the extended BMS algebra
Tuesday January 16, 2018 16:15:00 CET
Tuesday January 16, 2018 17:15:00 CET
Speaker: Dr. David A. Nichols
Room: SR 5 Helmholtzweg 4
The gravitational-wave memory effect is an unusual prediction of general relativity characterized by an asymptotically constant change in the gravitational-wave strain between early and late times. It produces a measurable effect for freely falling observers (a lasting displacement), it is generated by fluxes of matter and gravitational waves near null infinity, and it is closely related to the symmetry group of asymptotically flat spacetimes, the Bondi-Metzner-Sachs (BMS) group. Recently, however, there have been proposals that the symmetries of asymptotically flat spacetimes are the larger, extended BMS algebra. There are finite charges related to these additional symmetries, and changes in these charges produce a new kind of memory effect called spin memory. In this talk, I will introduce and discuss the gravitational-wave memory effect, the spin memory, and the conserved charges related to the extended BMS algebra. I will also discuss how these memory effects could be measured from binary black hole mergers using ground- and space-based gravitational-wave detectors.
SR 5, Helmholtzweg 4