* Previous studies have used charged antimatter like positrons and antiprotons, which they imply is kind of silly because the electromagnetic force is 10^42 times stronger than gravity, so you have to set up absolutely impossibly precise electromagnetic confinement apparatus to measure the relatively tiny gravitational force
* So instead, they formed anti-hydrogen (which is neutral), and shot them (10^6 at a time, as my understanding of the text goes?) into a vertical magnetic trap
* They waited for the anti-hydrogen to either "rise up" or "sink down" to the top or bottom walls of the apparatus and measured the frequency of annihilations
* They biased the vertical magnetic field to various values, to see, at what magnetic field bias, the "top" and "bottom" annihilations were exactly 50/50.
* If anti-matter is repulsive, they would expect to need a magnetic field bias that would "help the atoms stay down" to get to the 50/50 "top" and "bottom" rate.
* They measured that they needed a magnetic field bias applied to the anti-hydrogen equivalent to "pushing them up" with 0.75g (+/- 0.25g or so), so anti-matter is attractive. No new physics.
* 10^-13 % chance that anti-matter is repulsive
* Rules out quite a lot of cosmological work that used repulsive antimatter to explain various troublesome cosmology roadblocks (dark energy, etc.)