TITLE: complex submanifolds in complex euclidean space
QUESTION [6 upvotes]: Assume all manifolds are without boundaries. In Euclidean space $\mathbb{R}^n$, there are many submanifolds (Whitney Embedding Theorem). 
In complex Euclidean space $\mathbb{C}^n$,  are there any typical examples of  complex submanifolds ? 
My attempt: I only find the example: 
(1). for any $m\leq n$, $\mathbb{C}^m$ is a complex submanifold of $\mathbb{C}^n$. And an open subset of $\mathbb{C}^m$ is a complex submanifold of $\mathbb{C}^n$. 
(2). I find that any compact manifolds cannot be embedded as complex submanifolds of $\mathbb{C}^n$. 
Are there any other nontrivial examples of complex submanifolds in $\mathbb{C}^n$?

REPLY [3 votes]: Consider a holomorphic map  $f=(f_1,\dots,f_p):\mathbb C^n\to \mathbb C^p$ and its zero locus $X=\{x\in \mathbb C^n\vert f(x)=0\}$.
 If the jacobian matrix $(\frac {\partial f_i}{\partial x_j}(x))$  has rank $p$ at every $x\in X$, then $X\subset \mathbb C^n$ is a complex submanifold.
 The simplest example is a hypersurface i.e. the zero locus of a holomorphic function $f:\mathbb C^n\to \mathbb C $  whose gradient does not vanish on $X=f^{-1}(0)$.
 These hypersurfaces are exactly the closed submanifolds of dimension $n-1$ of $\mathbb C^n$. 
An explicit example
Take  $f(x_1,\ldots,x_n)=x_1^k+\cdots+x^k_n-1\:(k\in \mathbb N^*)$ and obtain the Fermat hypersurface $x_1^k+\cdots+x^k_n=1$, a submanifold of dimension $n-1$ of $\mathbb C^n$.