Negative mass might not defy Einstein

Repulsive matter could have played a role in early universe, computational study finds

Matter with negative mass, a seeming impossibility, could actually have existed in the early universe, a new study shows.

A novel solution to Einstein’s equations for gravity permits the existence of negative mass in a rapidly expanding universe like our own, physicists Manu Paranjape and Saoussen Mbarek of the University of Montreal report November 14 in Physical Review D.