Suppose f:*X*→Y is a morphism of schemes. We can define a function on the underlying topological space Y by sending y∈Y to the dimension of the fiber of f over y. When is this function upper ...
Let us work over the complex numbers for simplicity. Let $M$ be an affine algebraic monoid and $X$ an affine variety on which $M$ acts regularly, i.e. there is a morphism $\alpha: M\times X\to X$. Let ...