4 citations · 6 across the 4 of their papers we have counts for
4 papers
Coordinates, retracts and automorphisms
Yun-Chang Li
Let be a field of characteristic zero, be the polynomial ring in two variables. Let be an endomorphism of . It is proved that if maps each coord…
Endomorphisms preserving coordinates of polynomial algebras
Yun-Chang Li, Jie-Tai Yu
It is proved that the Jacobian of a k-endomorphism of k[x_1,...,x_n] over a field k of characteristic zero taking every tame coordinate to a coordinate, must be a nonzero constant…
Applications of degree estimate for subalgebras
Yun-Chang Li, Jie-Tai Yu
Let be a field of positive characteristic and be the free algebra of rank two over . Based on the degree estimate done by Y.-C. Li and J.-T. Yu, we extend the resu…
Degree estimate for subalgebras
Yunchang Li, Jie-Tai Yu
Based on Bergman's Lemma on centralizers, we obtain a sharp lower degree bound for nonconstant elements in a subalgebra generated by two elements of a free associative algebra over…