In my dissertation, I develop an account of integration in science based on the history of relativistic cosmology. Cosmology has been, and continues to be, remarkably successful in reconstructing the evolution of the universe over its 13.8 billion years. This success is somewhat surprising, if one examines the standard model of cosmology, ΛCDM ("Lambda-Cold Dark Matter"), in detail. The model incorporates particle physics, general relativity, classical mechanics and several other theoretical frameworks. Moreover, the evidence in support of ΛCDM ranges from large-scale structure surveys and the power spectrum of the anisotropies in the cosmic microwave background, over detailed hydrodynamical simulations, to high-energy physics experiments at particle accelerators. Integrating the different components together in one model requires overcoming hurdles like apparent contradictions between independent probes of the same feature of the world, or reconciling theoretical frameworks with incompatible assumptions.
I investigate how cosmologists have overcome these challenges throughout the twentieth century, and draw conclusions about what makes integration in cosmology successful. This not only provides an assessment of how cosmology came to achieve its current success, but it also provides a new perspective on philosophical accounts of integration that have been developed in context of the life sciences (see for example Bechtel 1986; Darden & Maull 1977; Love 2008; Mitchell 2003, 2009; Mitchell & Gronenborg 2017). Finally, it lays down the groundwork to investigate the epistemic warrant of the use of integrative disciplines to constrain new developments in the disciplines that fed into it – something that is at the forefront of contemporary research in physics beyond the standard model of particle physics.
Committee: John Norton (chair), Arthur Kosowsky, Sandra Mitchell, James Woodward