Addressing the High-$f$ Problem in Pseudo-Nambu-Goldstone Boson Dark Energy Models with Dark Matter - Dark Energy Interaction

Understand

We consider a dark energy scenario driven by a scalar field $\phi$ with a pseudo Nambu Goldstone boson (pNGB) type potential $V(\phi)=\mu^4 \left( 1+ {\rm cos}(\phi/f) \right)$.

• The pNGB originates out of breaking of spontaneous symmetry at a scale $f$ close to Planck mass $M_{\rm{pl}}$.
• We consider two cases namely the quintessence dark energy and the other, where the standard pNGB action is modified by the terms related to Slotheon cosmology.
• We demonstrate that for this pNGB potential, high-$f$ problem is better addressed when interaction between dark matter and dark energy is taken into account and that Slotheon dark energy scenario works even better over quintessence in this respect.