Island for one-sided Schwarzschild black hole

In this talk, I will give a brief introduction to recent progress on information loss paradox of one-sided Schwarzschild black hole. asymptotically flat black hole formed by gravitational collapse. Instead of Hartle-Hawking state, which is usually used in eternal black hole, we discuss island and page curve of "in" vacuum state which describes one-sided asymptotically flat black hole formed by gravitational collapse.