- #1
Simfish
Gold Member
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Hello there,
So I've noticed that at least out of the sources I've read, none of the point out the connection between additivity (a key operation that is emphasized on many texts) and homomorphisms. After all, a homomorphic function is merely a function wherein f(xy) = f(x)f(y). So a multiplicative function would be homomorphic under multiplication, and an additive function would be homomorphic under addition. Am I missing anything?
So is polynomial addition an isomorphism between the domain (the real line) and the range ONLY IF the function is monotonically increasing? (since bijectivity is a pre-req for isomorphism?) Is it a homomorphism otherwise?
(is this also true for the traditional functions we think about?)
So I've noticed that at least out of the sources I've read, none of the point out the connection between additivity (a key operation that is emphasized on many texts) and homomorphisms. After all, a homomorphic function is merely a function wherein f(xy) = f(x)f(y). So a multiplicative function would be homomorphic under multiplication, and an additive function would be homomorphic under addition. Am I missing anything?
So is polynomial addition an isomorphism between the domain (the real line) and the range ONLY IF the function is monotonically increasing? (since bijectivity is a pre-req for isomorphism?) Is it a homomorphism otherwise?
(is this also true for the traditional functions we think about?)
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