GRAVITATIONAL-WAVES FROM COALESCING BLACK-HOLE MACHO BINARIES

If MACHOs are black holes of mass similar to 0.5 M., they must have be en formed in the early universe when the temperature was similar to 1 GeV. We estimate that in this case in our Galaxy's halo out to similar to 50 kpc there exist similar to 5 x 10(8) black hole binaries the co alescence times of which are comparable to the age of the universe, so that the coalescence rate will be similar to 5 x 10(-2) events yr(-1) per galaxy. This suggests that we can expect a few events per year wi thin 15 Mpc. The gravitational waves from such coalescing black hole M ACHOs can be detected by the first generation of interferometers in th e LIGO/VIRGO/TAMA/GEO network. Therefore, the existence of black hole MACHOs can be tested within the next 5 yr by gravitational waves.