Description
The standard cosmological model has been established and its parameters are now measured with unprecedented precision. This model successfully describes observations from widely different epochs of the Universe, from primordial nucleosynthesis all the way to the present day. However, there is a big difference between modelling and understanding. Precision without accuracy is meaningless, hence the remarkable effort to discover, quantify mitigate and account for systematic errors. Here I will address a different type of systematic error: “what if the standard model is not quite right?”. How can cosmology go beyond (standard model’s) parameter fitting and at what cost? I will illustrate this with some examples including the cosmic distance ladder and the Cosmic Microwave Background.