inflated radii

Recently, the phrase inflated radii has commonly referred to the phenomena in hot Jupiters, some of which are much larger than would be expected given their mass and distance from their host star. Conventional models predict that gas planets more massive than Jupiter would remain close to Jupiter-sized unless internal fusion were providing energy. Thus a planet significantly larger than Jupiter poses the question of how that occurred. Possible explanations:

• intense stellar radiation.
• tidal heating (from the friction when tidal forces flex its material).
• Ohmic heating (i.e., electrical resistance heating, from electricity generated by a combination of surrounding magnetic fields, weather, etc.)