Translation guide
A mysterious form of energy in cosmology that is thought to drive the accelerating expansion of the universe. In Japanese, the term is typically expressed using the loanword ダークエネルギー or the calque 暗黒エネルギー.
Referring to the hypothetical form of energy that permeates space and causes the universe's expansion to accelerate.
A calque of 'dark energy', using the kanji for 'darkness' (暗黒). Less common than the katakana version but still understood.
Dark energy is thought to make up about 70% of the universe.