Cohomologie Locale Des Faisceaux Coherents (Sga 2): Seminaire De Geometrie Algebrique Du Bois Marie 1962 (Documents Mathematiques)
《Cohomologie Locale Des Faisceaux Coherents (Sga 2): Seminaire De Geometrie Algebrique Du Bois Marie 1962 (Documents Mathematiques)》 · 第 2 页 · Section 1.1「Definitions and Examples」，Example 1.1.1
For any group $G$ and commutative ring $R$, we can take $V=R$ and $\rho(g)=1$ for all $g\in G$, where $1$ denotes the identify map $R\to R$. This representation is called the trivial representation, and it is often denoted simply by its representation module $R$.