I am looking for a model answer for the following question:
Prove that there is a bijection between points of an algebraic variety $V$ over $\mathbb{C}$, and $Spec_{max}(\mathbb{C}[V])$ by following the sequential steps:
- For $x\in V$ define a map $\psi:\mathbb{C}[V]\to\mathbb{C}$ by $f\mapsto f(x)$. Prove that $\psi$ is a surjective ring homomorphism.
- Prove that the kernel of $\psi$ is a maximal ideal of $\mathbb{C}[V]$. Denote this maximal ideal by $\mathfrak{m}_x$.
- Define a map $\Psi:V\to Spec_{max}(\mathbb{C}[V])$ by $x\mapsto\mathfrak{m}_x$. Prove that $\Psi$ is injective.
- Using Hilbert’s theorem prove that $\Psi$ is surjective.
I have been trying to understand this for a while and getting nowhere, and have no solution/hint resource. Part (ii) is quite straightforward: using the ring homomorphism theorem $f(A)\cong A/ker(f)\,(A=\mathbb{C}[V])$. As $f(A)$ is a field, $ker(f)$ must be maximal. For the rest I am at a bit of a loss.
Many thanks