Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Hilbert's Theorem 90 and algebraic spaces   In modern form, Hilbert's Theorem 90 tells us that R^1f_*(G_m)=0, where f is
the canonical map between the etale site and the Zariski site of a scheme X. I
construct examples showing that the corresponding statement for algebraic
spaces does not hold. The first example is a nonseparated smooth 1-dimensional
bug-eyed cover in Kollar's sense. The second example is a nonnormal proper
algebraic space obtained by identifying points on suitable nonprojective smooth
proper schemes.

36
The categories of this paper are: cmp-lg
19
The categories of this paper are: eess
32
The categories of this paper are: atom-ph
5
The categories of this paper are: gr-qc
11
The categories of this paper are: hep-lat
12
The categories of this paper are: nucl-th
20
The categories of this paper are: acc-phys
14
The categories of this paper are: math-ph
28
The categories of this paper are: alg-geom
1
The categories of this paper are: cs
18
The categories of this paper are: econ
13
The categories of this paper are: quant-ph
23
The categories of this paper are: solv-int
0
The categories of this paper are: hep-ph
24
The categories of this paper are: dg-ga
17
The categories of this paper are: q-fin