Open main menu
Home
Random
Recent changes
Special pages
Community portal
Preferences
About Wikipedia
Disclaimers
Incubator escapee wiki
Search
User menu
Talk
Dark mode
Contributions
Create account
Log in
Editing
I-adic topology
(section)
Warning:
You are not logged in. Your IP address will be publicly visible if you make any edits. If you
log in
or
create an account
, your edits will be attributed to your username, along with other benefits.
Anti-spam check. Do
not
fill this in!
==Definition== Let {{mvar|R}} be a commutative ring and {{mvar|M}} an {{mvar|R}}-module. Then each [[ideal (ring theory)|ideal]] {{math|π}} of {{mvar|R}} determines a topology on {{mvar|M}} called the {{math|π}}-adic topology, characterized by the [[pseudometric space|pseudometric]] <math display=block>d(x,y) = 2^{-\sup{\{n \mid x-y\in\mathfrak{a}^nM\}}}.</math> The family <math display=block>\{x+\mathfrak{a}^nM:x\in M,n\in\mathbb{Z}^+\}</math> is a [[basis (topology)|basis]] for this topology.{{sfn|Singh|2011|p=147}} An {{math|π}}-adic topology is a [[linear topology]] (a topology generated by some submodules).<!-- but the converse is false, I think -->
Edit summary
(Briefly describe your changes)
By publishing changes, you agree to the
Terms of Use
, and you irrevocably agree to release your contribution under the
CC BY-SA 4.0 License
and the
GFDL
. You agree that a hyperlink or URL is sufficient attribution under the Creative Commons license.
Cancel
Editing help
(opens in new window)