Let $k$ be a field and suppose $p, q\in k$. We prove that the two affine
Hecke algebras $H_q$ and $H_p$ of type $A_n$ are isomorphic as $k$-algebras if
and only if $p=q^{\pm 1}$.
Let $\mathbb K$ be a field and suppose $p, q\in\mathbb K^*$ are not roots of
unity. We prove that the two quantum groups $U_q(\mathfrak {sl}_{n+1})$ and
$U_p(\mathfrak{sl}_{n+1})$ are isomorphic as $\mathbb K$-algebras implies that
$p=\pm q^{\pm 1}$ when $n$ is even. This new result answers a classical
question of Jimbo.
We consider isomorphisms and automorphisms of quantum groups. Let $k$ be a
field and suppose $p, q\in k^*$ are not roots of unity. We prove that the two
quantum groups $U_q(\mathfrak {sl}_2)$ and $U_p(\mathfrak{sl}_2)$ over a field
$k$ are isomorphic as $k$-algebras if and only if $p=q^{\pm 1}$. We also
describe the group of all $k$-automorphisms of $U_q(\mathfrak{sl}_2)$ and prove
that $\text{Aut}_k(U_q(\mathfrak {sl}_2))$ is isomorphic to
$\text{Aut}_k(U_p(\mathfrak {sl}_2))$
We consider isomorphisms and automorphisms of quantum groups. Let $k$ be a
field and suppose $p, q\in k^*$ are not roots of unity. We prove that the two
quantum groups $U_q(\mathfrak {sl}_2)$ and $U_p(\mathfrak{sl}_2)$ over a field
$k$ are isomorphic as $k$-algebras if and only if $p=q^{\pm 1}$. We also
describe the group of all $k$-automorphisms of $U_q(\mathfrak{sl}_2)$ and prove
that $\text{Aut}_k(U_q(\mathfrak {sl}_2))$ is isomorphic to
$\text{Aut}_k(U_p(\mathfrak {sl}_2))$