UnramDeg3 for GAP 4 ver.2019.09.26
Authors: Akinari Hoshi, Aiichi Yamasaki.Needs: GAP, version >=4.8.7; GAP package HAP, version >=1.11.15;
Current version: UnramDeg3-2019.09.26.zip (Hnminus1QoverZtoHnZfromResolution in H3nr.gap was modified)
Old version: UnramDeg3ver.2017.09.09.zip
Contact: Akinari Hoshi, Aiichi Yamasaki.
URL:
http://mathweb.sc.niigata-u.ac.jp/~hoshi/Algorithm/UnramDeg3/index.html
https://www.math.kyoto-u.ac.jp/~yamasaki/Algorithm/UnramDeg3/index.html
Description
This code provides algorithms for computing unraified and stable cohomologies of degree 3 for fields of invariants.Installation
Download UnramDeg3-2019.09.26.zip and unpack it to some folder , e.g. C:\Users\username.Then type "Read("H3nr.gap");" on GAP.
Documentation
H3nr [.html, .pdf]README [.html, .pdf]
Content
UnramDeg3-2019.09.26.zip-+-H3nr.gap +-H3nr.pdf +-README.txt +-README.pdf +-UnramDeg3-2019.09.26.pdf
References
[HKY20] Akinari Hoshi, Ming-chang Kang and Aiichi Yamasaki,
Degree three unramified cohomology groups and Noether's problem for groups of order 243,
J. Algebra 544 (2020) 262-301.
ScienceDirect
Extended version:
arXiv:1710.01958.
[Pe08] Emmanuel Peyre,
Unramified cohomology of degree 3 and Noether's problem,
Invent. Math. 171 (2008) 191-225.