1 Ergodic theory References for this section: CFS]. 1. The basic setting of ergodic theory: a measure-preserving transformation T of a probability space (X; B; m). Usually we assume T is invertible. (More generally, measure-preserving means R f T = R f; equivalently, m(T ?1 (A)) = mA.) How many measure spaces are there? Standard Borel spaces: any Borel subset of a complete, separable metric spa...

Until now only for special classes of infra-solvmanifolds, namely, infra-nilmanifolds and infra-solvmanifolds type (R), there was a formula available computing the Nielsen number self-map on those manifolds. In this paper, we provide general averaging which works all self-maps possible reduces to old formulas in case or (R). Moreover, when viewing an infra-solvmanifold as polynomial manifold, r...

In this paper, we consider the moduli space SUC(r,OC) of rank r semistable vector bundles with trivial determinant on a smooth projective curve C of genus g. When the rank r = 2, F. Kirwan constructed a smooth log resolution X → SUC(2,OC). Based on earlier work of M. Kerr and J. Lewis, Lewis explains in the Appendix the notion of a relative Chow group (w.r.to the normal crossing divisor), and a...

We first give a new proof and also a new formulation for the Abhyankar-Gujar inversion formula for formal maps of affine spaces. We then use the reformulated Abhyankar-Gujar formula to give a more straightforward proof for the equivalence of the Jacobian conjecture with a special case of the vanishing conjecture of (homogeneous) quadratic differential operators with constant coefficients.

Let F (z) = z−H(z) with order o(H(z)) ≥ 1 be a formal map from C to C and G(z) the formal inverse map of F (z). We first study the deformation Ft(z) = z − tH(z) of F (z) and its formal inverse Gt(z) = z + tNt(z). (Note that Gt=1(z) = G(z) when o(H(z)) ≥ 2.) We show that Nt(z) is the unique power series solution of a Cauchy problem of a PDE, from which we derive a recurrent formula for Gt(z). Se...

Let F (z) = z−H(z) with order o(H(z)) ≥ 1 be a formal map from C to C and G(z) the formal inverse map of F (z). We first study the deformation Ft(z) = z − tH(z) of F (z) and its formal inverse Gt(z) = z + tNt(z). (Note that Gt=1(z) = G(z) when o(H(z)) ≥ 2.) We show that Nt(z) is the unique power series solution of a Cauchy problem of a PDE, from which we derive a recurrent formula for Gt(z). Se...

In this paper it is proved that a power linear Keller map of dimension three over a field of characteristic zero is linearly triangularizable. Let K be a field. A polynomial map F in dimension n over K is an n-tuple (F1, F2, · · · , Fn) of polynomials in K[X1, X2, · · · , Xn]. If G is another polynomial map of the same dimension, then the composition of F and G is defined by F ◦G = (F1(G1, G2, ...

In the recent progress [BE1], [M] and [Z2], the wellknown Jacobian conjecture ([BCW], [E]) has been reduced to a problem on HN (Hessian nilpotent) polynomials (the polynomials whose Hessian matrix are nilpotent) and their (deformed) inversion pairs. In this paper, we prove several results on HN polynomials, their (deformed) inversion pairs as well as the associated symmetric polynomial or forma...

In the recent work [BE1], [M], [Z1] and [Z2], the well-known Jacobian conjecture ([BCW], [E]) has been reduced to a problem on HN (Hessian nilpotent) polynomials (the polynomials whose Hessian matrix are nilpotent) and their (deformed) inversion pairs. In this paper, we prove several results on HN polynomials, their (deformed) inversion pairs as well as on the associated symmetric polynomial or...