Yuri Milner, the Russian entrepreneur, philanthropist and self-described “failed physicist” who made a splash two years ago when he began handing out lavish cash awards to scientists, is expanding the universe of his largess again: He and Mark Zuckerberg of Facebook announced Thursday night that they would begin handing out $3 million awards to mathematicians.

Starting next year, the Breakthrough Prize in Mathematics, as it will be called, will join the Fundamental Physics Prize, which Mr. Milner established in 2012, and the Breakthrough Prize in Life Sciences, which he set up a year ago in partnership with Sergey Brin of Google, Mr. Zuckerberg and Jack Ma, a Chinese entrepreneur, and their families. Each winner or winning team gets $3 million, making the awards the richest in science (this year’s Nobel Prize winners, for example, are each winning or sharing $1.2 million).

Also on Thursday, the latest winners of the life sciences and physics awards were named and honored at a black-tie dinner and ceremony at the Ames Research Center in Mountain View, Calif., co-hosted by Vanity Fair magazine and presided over by the actor Kevin Spacey. Six of the honorees are life scientists, each of whom won $3 million for work toward curing disease or extending life, and two are physicists who helped develop string theory, who split another $3 million. All are men.

The life scientists are: James P. Allison, of the University of Texas MD Anderson Cancer Center; Dr. Mahlon R. DeLong, professor of neurology at Emory University; Michael N. Hall, a biochemist at the Biozentrum of the University of Basel in Switzerland; Robert Langer, a professor at the Massachusetts Institute of Technology; Dr. Richard P. Lifton, a geneticist at the Yale School of Medicine; and Alexander Varshavsky, a cell biologist at the California Institute of Technology.