Mass Hierarchies and Dynamical Field Range

Understand

Several swampland conjectures suggest that there is a critical field range beyond which the effective field theory (EFT) description breaks down in quantum gravity.

• In applications of these conjectures, however, the field range of interest is the field space distance traced by the physical trajectory that solves the equations of motion.
• We refer to this field space distance as the dynamical field range.
• We show that in the absence of a mass hierarchy between the light and heavy fields, the trajectory of the light field does not, in general, follow a geodesic in field space.