Structure formation beyond shell-crossing: nonperturbative expansions and late-time attractors

Understand

Structure formation in 1+1 dimensions is considered, with emphasis on the effects of shell-crossing.

• The breakdown of the perturbative expansion beyond shell-crossing is discussed, and it is shown, in a simple example, that the perturbative series can be extended to a transseries including nonperturbative terms.
• The latter converges to the exact result well beyond the range of validity of perturbation theory.
• The crucial role of the divergences induced by shell-crossing is discussed.