Question

In thinking about the singularity at the base of the Big Bang which sparked the present universe, some theories about what in turn formed that singularity include ...?

Answer 1

String theory
The string theory involves movement and/or collision of branes, physical point particles with mass (and possibly charge) which can propagate according to the rules of quantum mechanics. Cold Big Bang involves designation of an absolute zero temperature at the beginning of the Universe; Steady-state model theory denies that Big Bang has a place at all in an eternal Universe; Big Freeze describes the Universe's possible end.