Gauvain Leconte-Chevillard and Andrea Roselli (UNamur)

Title : Did the laws of physics emerge at t=10^-34 s?

Abstract : 
According to the vast majority of the inflationary models of the universe, the exponential expansion of space ends ≃10^-34 s after the Big Bang with a phase of reheating during which the inflation field decays into the particles of the Standard Model. In this talk, we do not address issues regarding the empirical adequacy of this cosmological scenario; we rather focus on the two following questions:

– According to this scenario, can we argue that the particles of the Standard Model emerged from the inflation field, and in which sense?

– If we claim that the interaction carriers of the Standard Model (e.g. gluons) emerged during the reheating, does it mean that thelaws describing or governing these interactions (e.g. the strong nuclear force) emerged at the same time?

In the first part of the talk, we give a brief overview of the physics underlying the reheating of the universe at the end of inflation. Then, in the second part, we claim that the models of reheating are sufficiently developed to answer unambiguously to the first question – if and only if we are careful to distinguish two kinds of emergence: synchronic and diachronic. However, such a precise answer might not be available for the second question, which depends on our metaphysical conception of physical laws. In the last part, we will present a metaphysical conception that could elegantly accommodate the physical claims made above, we will show how things would “hang together” in such a metaphysics, and make some more general philosophical remarks.

The seminar will take place in Room S08 at the Faculty of Sciences.