Critical exponent of a word

In the context of formal languages and automata theory, the term "critical exponent" of a word refers to a specific property related to the repetitions of substrings within that word. More formally, for a finite word \( w \), the critical exponent \( e(w) \) is defined as the smallest integer \( n \) such that the word can be represented as the concatenation of \( n \) or more identical blocks. For example, consider the word \( w = aabb \).