Without End: A Short Story of Hope — Kristine Kathryn Rusch

When Dylan's wife, Geneva, dies, Dylan refuses to believe it. Not because he believes in ghosts, but because he believes in science. Geneva, a physicist, believed humans could overcome the perception of linear time. If her theories hold true, Dylan can change his perceptions and Geneva will live again. He has nothing to lose, and Geneva to gain.
“Rusch writes humanist SF. Her lead characters (most notably the wife/brilliant physicist in “Without End”) exhibit lively intellects spurred on by keen imaginations, and are capable of both compassion and love. Such complex natures can lead to emotional suffering, but also to Rusch's special version of the “happy ending” -- a transcendence of grief, guilt, sometimes even mortality…” -- Locus