TAPIR Seminar

Einstein's general relativity is 100 years old. Hailed by Bertrand Russell as "the greatest synthetic achievement of the human intellect," the theory has passed all experimental verifications with flying colors. Despite these triumphs, cosmological observations and the well known difficulties in quantizing gravity suggest that general relativity should be modified at some level. All of these modifications violate some crucial assumptions underlying general relativity, and (if observed) they may provide important clues on the nature of dark matter, dark energy and quantum gravity.

Strong-field modifications of general relativity (if they occur in nature) are most likely to leave experimental signatures in compact objects such as black holes and neutron stars. Therefore compact objects - whether in isolation or in binary systems - are excellent astrophysical laboratories for high-energy physics and strong-field gravity. The gravitational radiation emitted during their inspiral and merger of compact binaries encodes important information on their astrophysical formation mechanism, and it will allow us to test strong gravity in unprecedented ways. After a short review of current experimental verifications of general relativity, I will discuss potential smoking guns of modified gravity in gravitational-wave detectors, and the theoretical and observational challenges associated with their search.