2

Describe: 1) Hom(Q/Z->Q) 2) Hom(Q->Q/Z) Q rational numbers Z integers

My thoughts 1) Q/Z i can describe as a/b, a,b coprime and smaller than 1. So I thought Hom(Q/Z->Q) I can describe as [f:a+N->b, N subgroup of Q/Z, a element of Q, b any element of a+N].

2) Hom(Q->Q/Z) = [f:a->a+N, where N any subgroup of Q/Z]

Is this correct?

user26857
  • 52,094
  • No, not correct. Also, this is not the correct forum for your question. (Think about how 1/7 gets mapped in either case. What can f(1/7) possibly be?) –  Oct 13 '14 at 05:10
  • I got my fault in 1). is 2) correct? –  Oct 13 '14 at 05:24
  • Good question, wrong website --- we do research at MO. – Gerry Myerson Oct 13 '14 at 05:41
  • I don't think so. In 2), what is f(22/7)? Your suggestion does not handle 22/7 as I read it. You might ask on math.stackexchange instead. –  Oct 13 '14 at 05:41

0 Answers0