On negative mass cosmology in General Relativity

In this Letter we present strong arguments in favour of thoroughly revising the negative mass cosmology (NMC), which has been proposed as a simple alternative explanation dark energy and matter effects, within framework General Relativity. We show that there are various physical predictions model require fine-tuning order to make them compatible with current cosmological surveys. way, original motivation NMC becomes obscured due imposition fine-tuned unknown variables. conclude more rigorous theoretical treatment is needed viable model.