Was there a Big Bang?

The idea that our Universe emerged as a result of the extraordinary power of
the Big Bang from singularity (i.e., a state of an infinitely small quantity and
infinitely high concentration of matter) is still very popular today. It was one
of the main postulates of the Big Bang theory that completely formed in the
1960s–1970s. However, at present this idea as well as the Big Bang theory is
outdated, although it is still shared by many scientists. Being widespread
since the end of the 1970s the Inflation theory appears more modern. The
main reason for the emergence of the Inflation theory was that the Big Bang
theory could not satisfactorily explain a number of the contemporary parameters
of the Universe.
The Inflation theory makes still widespread views of the Big Bang theory
archaic as regards the following points: 1) the history of the Universe started
with the Big Bang; 2) it started with the singularity. According to the Inflation
theory, the Big Bang was not the beginning and the moment of the origin of the
Universe, but it was preceded by at least two epochs: inflation and postinflationary
heating. That is, the Big Bang or precisely the hot Big Bang is just
a phase transition from the state of cold inflation to the hot phase. Since the
Inflation theory does not consider the Big Bang as the initial phase there
emerges an intricate problem of the role of the Big Bang in the process of
the formation the Universe as a whole. The paper considers the confusion
with the Big Bang notion, a number and sequence of ‘bangs’ and why the theory
can dispense easily without the notion the Big Bang. We will also discuss
some advantages and disadvantages of the Inflation theory.