# Black hole area theorem and Hawking radiation

Black hole area theorem states that surface area of a black hole does not decrease with time (see page 10 of Introductory Lectures on Black Hole Thermodynamics, Ted Jacobson http://www.physics.umd.edu/grt/taj/776b/lectures.pdf). How then does the surface area of a Black hole decrease via Hawking radiation? Is it because mass of black hole decreases or one of the assumptions of the theorem is violated?

Thanks!

• Minor comment to the post (v1): Please consider to mention explicitly author, title, etc. of link, so it is possible to reconstruct link in case of link rot. – Qmechanic Mar 12 '15 at 15:20