Extra dimensions of space: science or fiction?

In this (hopefully) pedagogical talk I explain why it is useful to contemplate extra dimensions of space and how it can change the way we think about the cosmological constant problem. I will focus on the simple classical dynamics of extra dimensions, whether extra dimensions can be (dinamically) hidden from us, and whether the alter our view on the early universe. This talk is aimed at a a general audience of theoretical physicist.

This talk is related to the I+D+i project whose reference is CEX2020-001007-S, funded by MCIN/AEI/10.13039/501100011033. The topic is framed within the following research line: Strings and quantum gravity (Gravity/Strings).