I would like to know if someone has an explicit example for the rank of the Neron-Severi group of a normal crossing scheme (proper over a field) being different from the rank of the kernel of $NS(X^{(0)})\to NS(X^{(1)})$, the restriction map from the Neron-Severi group of the components to the Ne...

I would like to know if someone has an explicit example for the rank of the Neron-Severi group of a normal crossing scheme (proper over a field) being different from the rank of the kernel of $\operatorname{NS}(X^{(0)})\to \operatorname{NS}(X^{(1)})$, the restriction map from the Neron-Severi gro...

I am having trouble calculating this integral: $$ g(a) = \int_{0}^{\frac{\pi}{2}} \frac{\arctan(a \tan x)}{\tan x}dx $$ I tried calculating $g'(a)$ but then I get stuck.

If a poster includes in the title some formula in enclosed between $$, like $$x^2+y^2=z^2$$ $$x^2+y^2=z^2$$ the title of the question will take up more space in various lists of questions, like here or here. I guess that we can agree that this is not a good way to use MathJax (LaTeX) in titles. ...