Abstract Loday's 1-cat group definition plays very powerful role in making
some new applications to crossed module due to Whitehead.  There
are  many  applications of cat$^1$-groups such as
cat$^1$-polygroups and pullback cat$^1$-polygroups. The importance of hypergroups come from the
properties of hypergroups such that hypergroups in the sense of
Marty  do not have identity element, inverse element and they are
generalization of the well known groups. In this paper,  we introduce the concept of  cat$^1$-hypergroups, their examples and some related properties.
Also, we investigate pullback cat$^1$-hypergroups and properties such as: every cat$^1$-group is a cat$^1$-hypergroup; construction of  a cat$^1$-group from a crossed module of hypergroups and vice versa. Finally,  we  present  the definition of pullback cat$^1$-hypergroups and some of their properties.  
  |