## New answers tagged complex-geometry

1
vote

### Nonequidimensional birational Mori contractions

Let
$$
Y = \left\{ A = \left(\begin{smallmatrix}
a_{11} & a_{12} & a_{13} \\
a_{21} & a_{22} & a_{23}
\end{smallmatrix}\right)
\right\} \cong \mathbb{A}^6.
$$
Let also
$$
X = \{ (A,...

4
votes

### Vector bundles on $\mathbb{P}^1$

Consider the exact sequence, $0\to E(-1)\to E\to E_p\to 0$, where the first map is just multiplication by $x$. Then $E_p$ is just the skyscraper sheaf at $p=(0,1)$. Taking cohomologies you get $0\to \...

8
votes

Accepted

### Is the Gödel universe Wick rotatable?

$\DeclareMathOperator\SL{SL}$Clearly, as Robert Bryant indicates, it is Wick-rotatable to a different Lorentzian space. However, it is also Wick-rotatable to a Riemannian space, albeit negative ...

1
vote

### Solution to $a=e^t (t-r_1)(t-r_2)$ with Lambert $W$ function, where $r_1, r_2 $ are complex

This equation cannot be solved in terms of the Lambert $W$ function or any other known functions -- even if a, r1, and r2 are real, let alone complex.
Here is what Mathematica says about this:

8
votes

### Is the Gödel universe Wick rotatable?

I may be misreading the sources that you list for the definition of Wick-rotatable, but, I believe that the following construction does fit that definition: According to the Wikipedia page that the ...

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