The most common and acceptable theory about the creation of universe is â€œthe big bang theoryâ€ which suggests that there was a very small point of light having unimaginable density and heat energy which exploded spontaneously nearly 15 billion years ago just before the beginning of universe. This theory has come up with the explanation of many mechanisms of universe but still there are a lot many questions which have not been answered yet.
A theory is given by Andrei Linde a professor in physics which is known as â€œthe self reproducing inflationary universeâ€ and it claims that new universes are constantly spawned by the universe in a fraction of a second. If the inflation field energy falls below a particular level then space stops to expand and the left energy changes the particles which form the universe. This inflation can be a big bang for a new universe. Our place in the universe is too less in energy to produce a new universe but other regions can if the energy reaches to a certain level. The same might has happened with our universe. In one of his interviews Linde said that if life disappears from our place then it can take birth again at some other place. Because of the resistance of other scientists about it he said that it is a very simple theory but we are not accepting it because of our psychological barriers.
How the universe came into existence is still debated. A lot more discoveries still have to be made to know its origin. Whether god created universe or something like big bang had happened we are not sure about it but we know that something big had happened resulting in the universe.