Speaker
Description
The gravitational-wave (GW) memory effect is characterized by a persistent offset in the GW strain, which is closely related to the infrared physics of asymptotically flat spacetimes. There are ongoing searches for the memory effect from the mergers of binary black holes, which have been observed by the LIGO-Virgo-KAGRA collaboration. I will discuss how these detectors search for the memory effect and what aspects of the memory effect can be probed by them. The memory effect is just the leading-order persistent GW effect in a hierarchy of "higher GW memory effects" that are related to multiple time integrals of the news tensor (the radiative degrees of freedom in asymptotically flat spacetimes). The next order contains the spin and center-of-mass memory effects (collectively, the drift memory); one order higher are the ballistic memory effects. I also will discuss the definitions of these higher memory effects, the features of the GW strain related to these effects in binary black hole mergers, and their detection prospects.