The Cauchy kernel for cones
A new representation of the Cauchy kernel for an arbitrary acute convex cone Γ in ℝⁿ is found. The domain of holomorphy of is described. An estimation of the growth of near the singularities is given.
A new representation of the Cauchy kernel for an arbitrary acute convex cone Γ in ℝⁿ is found. The domain of holomorphy of is described. An estimation of the growth of near the singularities is given.
For any holomorphic function F in the unit polydisc Uⁿ of ℂⁿ, we consider its restriction to the diagonal, i.e., the function in the unit disc U of ℂ defined by F(z) = F(z,...,z), and prove that the diagonal mapping maps the mixed norm space of the polydisc onto the mixed norm space of the unit disc for any 0 < p < ∞ and 0 < q ≤ ∞.
We show that a convex totally real compact set in admits an extremal array for Kergin interpolation if and only if it is a totally real ellipse. (An array is said to be extremal for when the corresponding sequence of Kergin interpolation polynomials converges uniformly (on ) to the interpolated function as soon as it is holomorphic on a neighborhood of .). Extremal arrays on these ellipses are characterized in terms of the distribution of the points and the rate of convergence is investigated....
We describe the polynomials P ∈ ℂ[x,y] such that . As applications we give new examples of bad field generators and examples of families of polynomials with smooth and irreducible fibers.
Let be the open upper light cone in with respect to the Lorentz product. The connected linear Lorentz group acts on and therefore diagonally on the -fold product where We prove that the extended future tube is a domain of holomorphy.
The algebraically closed field of Nash functions is introduced. It is shown that this field is an algebraic closure of the field of rational functions in several variables. We give conditions for the irreducibility of polynomials with Nash coefficients, a description of factors of a polynomial over the field of Nash functions and a theorem on continuity of factors.