arXiv subjects
Publications and source records attributed to Seppo I Hiltunen.
By an example we show that Olaf Mueller's assertion about his new theorems being able to give anew some classical results previously obtained via applications of Nash--Moser type theorems is unfounded. We also give another example indicating some limitations in possible applications of related new inverse function theorems.
We prove holomorphy E sqcap C(I,varPi) to C(I,varPi) of the map (x,y) mapsto x circ [id,y] where [id,y]:I owns t mapsto (t,y(t)) for a real compact interval I, and where varPi is a complex Banach space and E is a certain locally convex space of continuous functions x:I times varPi to varPi for which x(t,.) is holomorphic for all t in I. We also discuss application of this result to establishing a holomorphic solution map (xi,varphi) mapsto y for functions y:I to varPi satisfying the ordinary differential equation y' = varphi circ [id,y] with initial condition y(t_0) = xi .
This note aims to clarify the interrelations of certain inequivalently defined Banach spaces denoted by C^i(\barΩ) for a natural number i and a bounded open set Ω. We give some sufficient conditions for the equality of these spaces, and present examples to show that the spaces indeed can be unequal for Ωhaving irregular boundary.
This article is centered around generalizing a previous implicit function theorem of the author to be applicable for maps f:E sqcap F to F which can be lifted to Keller C^k_pi maps f_i:E sqcap F_i to F_i with F_i Banach and F=projlim F_i . We prove theorems about existence and differentiability of functions g satisfying f(x,g(x))=b constant. In addition to these abstract theorems, we give several examples of applications to proving smooth dependence of the solution on initial/boundary values and the nonlinearity in nonlinear (partial) differential equations.