Expansion Of Bubbles In Inflationary Universe

We show that particle production during the expansion of bubbles of true vacuum in the sea of false vacuum is possible and calculate the resulting rate. As a result the nucleated bubbles cannot expand due to the transfer of false vacuum energy to the created particles inside the bubbles. Therefore all the inflationary models dealing with the nucleation and expansion of the bubbles (including extended inflation) may not be viable. 1 mohazzab@het.brown.edu. Current address: Box 1843, Physics Dept. Brown University, Providence, RI 02912, USA 2 salehi@netware2.ipm.ac.ir 1 Introduction The idea of inflation ([?], [?]) solves many problems of old cosmology such as horizon problem. The main idea in inflationary models is the rapid expansion of the early universe (e 50 times the initial value) in a very short time. (In fact inflationary models are not the only candidate that can solve the horizon problem. There is a recent claim that this problem can be solved as a byproduct original i..