Inflaton fragmentation in E-models of cosmological $\alpha$-attractors

Understand

Cosmological $\alpha$-attractors are observationally favored due to the asymptotic flatness of the potential.

• Since its flatness induces the negative pressure even after inflation, the coherent oscillation of the inflaton field could fragment into quasi-stable localized objects called I-balls (or "oscillons").
• We investigated the possibility of I-ball formation in E-models of $\alpha$-attractors.
• Using linear analysis and the lattice simulations, we find that for $\alpha\lesssim10^{-3}$, the inflaton feels the negative pressure long enough and actually fragments into I-balls.