Theorem
Schur's Lemma
Let $(V, \rho)$ and $(W, \sigma)$ be irreducible $G$-representations (Definition~Irreducible Representation) over an algebraically closed field, and let $T : V \to W$ be an intertwiner (Definition~Morphism of Representations).
- Either $T = 0$ or $T$ is an isomorphism.
- If $V = W$, then $T = \lambda\, \mathrm{id}_V$ for some $\lambda \in k$.
Dependency Graph
flowchart LR
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nc8a0881e["Irreducible Representation"]
nf70e3a35["Morphism of Representations"]
n36e5bd4f["Schur's Lemma"]:::current
nb96526a2["Remark"]
n1b852777["Character Table of $S_3$"]
nc8a0881e --> n36e5bd4f
nf70e3a35 --> n36e5bd4f
n36e5bd4f --> nb96526a2
n36e5bd4f --> n1b852777
click nc8a0881e "../objects/c8a0881e.html" "_self"
click nf70e3a35 "../objects/f70e3a35.html" "_self"
click nb96526a2 "../objects/b96526a2.html" "_self"
click n1b852777 "../objects/1b852777.html" "_self"