In classical theory of distributions (Schwartz–Sobolov theory), nonlinear operations such as multiplication of distributions are forbidden (Schwartz impossibility theorem). Colombeau’s theory of new generalized functions provides a consistent framework to perform such operations. In this paper, using Colombeau algebra, we construct a signature changing cosmological model for beginning of the universe. Our model considers two different manifolds with a common signature changing boundary in which creation of the universe occurs as a quantum mechanical tunneling effect at this boundary. As an important result, we find a geometric interpretation of cosmological constant.
