Ruled Surfaces with Non-trivial Surjective Endomorphisms
نویسنده
چکیده
Let X be a non-singular ruled surface over an algebraically closed field of characteristic zero. There is a non-trivial surjective endomorphism f : X → X if and only if X is (1) a toric surface, (2) a relatively minimal elliptic ruled surface, or (3) a relatively minimal ruled surface of irregularity greater than one which turns to be the product of P and the base curve after a finite étale base change.
منابع مشابه
Compact Complex Surfaces Admitting Non-trivial Surjective Endomorphisms
Smooth compact complex surfaces admitting non-trivial surjective endomorphisms are classified up to isomorphisms. The algebraic case has been classified in [3], [19]. The following surfaces are listed in the non-algebraic case: a complex torus, a Kodaira surface, a Hopf surface with at least two curves, an Inoue surface with curves, and an Inoue surface without curves satisfying a rationality c...
متن کاملSeparable Endomorphisms of Surfaces in Positive Characteristic
The structure of non-singular projective surfaces admitting non-isomorphic surjective separable endomorphisms is studied in the positive characteristic case. The case of characteristic zero is treated in [2], [16] (cf. [3]). Many similar classification results are obtained also in this case; on the other hand, some examples peculiar to the positive characteristic are given explicitly.
متن کاملEndomorphisms of Partially Ordered Sets
Let P be a partially ordered set. A function φ : P → P is an endomorphism of P if for every two elements x, y of P , the inequality φ(x) 6 φ(y) holds whenever x 6 y. Obviously, the identity mapping is a (trivial ) endomorphism. Here, however, we will be interested in endomorphisms with an image of size less than |P |, i.e. endomorphisms which are not automorphisms of P . We will refer to them a...
متن کاملStrongly clean triangular matrix rings with endomorphisms
A ring $R$ is strongly clean provided that every element in $R$ is the sum of an idempotent and a unit that commutate. Let $T_n(R,sigma)$ be the skew triangular matrix ring over a local ring $R$ where $sigma$ is an endomorphism of $R$. We show that $T_2(R,sigma)$ is strongly clean if and only if for any $ain 1+J(R), bin J(R)$, $l_a-r_{sigma(b)}: Rto R$ is surjective. Furt...
متن کاملAn F-space with Trivial Dual and Non-trivial Compact Endomorphisms
We give an example of an F-space which has non-trivial compact endomorphisms, but does not have any non-trivial continuous linear functionals.
متن کامل