We model the standard ΛΛCDM model of the universe by the spatially flat FLRW line element
which we
extend for all time
t∈(−∞,∞). Although there is a cosmological singularity at the big bang
t=0, since the spatial part of the metric collapses to zero, nevertheless, this line element is defined for all time
t∈(−∞,∞), is
C∞ for all
t≠0, is
C1 differentiable at
t=0, and
is non-degenerate and solves Friedmann’s equation for allt≠0. Thus, we can use this
extended line element to model the universe from its past-asymptotic initial state
dS−4 at
t=−∞, through the big bang at
t=0, and onward to its future-asymptotic final state
dS+4 at
t=∞. Since in this model the universe existed
before the big bang, we conclude that (1) the universe was
not created
de novo at the big bang and (2) cosmological singularities such as black holes or the big bang itself need not be an end to spacetime. Our model shows that the universe was asymptotically created
de novo out of nothing at
t=−∞ from an
unstable vacuum negative half de Sitter
ds2dS−4 initial state and then dies asymptotically at
t=∞ as the
stable positive half de Sitter
ds2dS+4 final state. Since the de Sitter states are vacuum matter states, our model shows that the universe was created from nothing at
t=−∞ and dies at
t=∞ to nothing.