  Exploring the fundamental constituents of the matter around us and in the
Universe, as well as their interactions, is among the premier goals of physics.
Investigating ultrarelativistic collisions in particle accelerators has
delivered answers to these questions many times in the past decades. In this
paper we focus on the research aimed at recreating the matter that filled the
Universe in the first microsecond after the Big Bang -- but this time in
collisions of heavy ions. In particular we discuss the technique called
femtoscopy, which provides us a tool to understand the space-time structure of
particle creation in heavy-ion collisions. We utilize Levy-stable distributions
to investigate this structure and explore its dependence on particle momentum
and collision energy.
