[safina]

I hope this helps

First of all you need to know that energy of matter equals energy of antimatter.At the time of big bang everything was concertrated at one point and there was no matter or antimatter.It's because of the reason the singularity was at higher temperature.As all body at some temperature constantly radiates heat singularily did same and gradually started cooling.It was during this process that the reverse of Einstein equation worked and energy was converted to matter.Same amount of matter and antimatter was created in this process.As this substances are created,there arose a repulsion between them and in due coarse of time when this repulsion became greater than the net attraction between the matter ,occured the Big Bang and our very own universe was created