Recently some articles in popular media1, 2 informed that LIGO will be able to measure the memory effect of gravitational waves described by Demetrios Christodoulou in 1991.3
The measurement method based on accumulation over many LIGO measurements was proposed by Paul D. Lasky and colleagues.4
I do not understand most of the details in the paper4 but a mystery for me is how do they count with the effect of gravitational waves which are out of measurement range of LIGO (either by frequency or amplitude). I think we cannot make many assumptions about such waves. Is the paper4 reasonable?
- Charles Q. Choi "Gravitational Waves May Permanently Alter Spacetime"
- "Advanced LIGO Gravitational Wave Observatory Could Detect Permanent Memory of Spacetime"
- D. Christodoulou (1991). "Nonlinear nature of gravitation and gravitational-wave experiments". Phys. Rev. Lett. 67 (12): 1486–1489.
- Paul D. Lasky, Eric Thrane, Yuri Levin, Jonathan Blackman, Yanbei Chen (2016). "Detecting gravitational-wave memory with LIGO: implications of GW150914"