Newton geometry of Bogdanov-Takens degeneracies in integrable dilatonic models: invariant divisors and boundary multiplicity

E. Chan-López, A. Martín-Ruiz, J. M. Paulin Fuentes

The Kantowski--Sachs interior of Grumiller's two-dimensional dilaton gravity model reduces to $\dot{H}=\frac{1}{2}(\Lambda -3H^2-u^2)+Qu$, $\dot{u}=-Hu$, where $H$ is the expansion rate of the…