March 19 (UPI) -- Physicist Stephen Hawking worked up to his death last week and submitted a paper on the end of the universe, his co-author said.
Hawking's scientific paper "A Smooth Exit from Eternal Inflation," written with Thomas Hertog of Belgium's Leuven University, was revised from a July 2017 draft and submitted on March 4. Hawking died Wednesday at age 76.