The wave equation near flat Friedmann-Lemaître-Robertson-Walker and Kasner Big Bang singularities

Artur Alho, Grigorios Fournodavlos, Anne T. Franzen

We consider the wave equation, ${\square }_g\psi =0$, in fixed flat Friedmann-Lemaître-Robertson-Walker and Kasner spacetimes with topology ${\mathbb{R}}_{+}\times {\mathbb{T}}^3$. We obtain gen…