Speaker
Description
Since the first detection of gravitational waves from binary black hole mergers, a key question has been how such massive black holes—often exceeding 30 M⊙—are formed in the Universe. Recent results from GWTC-4 have even reported multiple black holes with masses beyond 100 M⊙, posing new challenges to our understanding of stellar evolution and compact-object formation. In this talk, I will review the possible astrophysical and cosmological origins of massive binary black holes, including isolated binary evolution channels, dynamical formation in dense stellar systems, remnants of Population III (first-generation) stars, and primordial black holes formed in the early Universe. Particular emphasis will be placed on the formation of black holes in low-metallicity environments and the role of binary interactions. I will also discuss how the rapid progress of gravitational-wave observations, combined with theoretical population-synthesis and stellar-evolution calculations, can help us unveil the origin and cosmic history of massive black-hole binaries.
