Any field that is finitely generated as a ring is a finite field.

# Author: fmartin

# Outside in

Given a group , embed in a larger group such that any automorphism of is the restriction of an inner automorphism of .

# Squaring the circle

Is there a bijection of the plane sending every circle to a square?

# Spooky algebra II

Exhibit a group , a set of generators for and a subgroup such that for all and yet is not normal in .

# It’s counting time

What is the number of idempotent functions ?

# A two-liner

Is there a ring such that there are two different ring injections ?

# Still expecting my fix

What’s the expected number of fixed points of a uniformly distributed random permutation of elements?