BackgroundA formal power series f (x 0 , x 1 , . . . , x n ) with coefficients in C is said to be convergent if it converges absolutely in a neighborhood of the origin in C n+1 . A classical result of Hartogs (see [5]) states that a series f converges if and only if f z (t) := f (z 0 t, z 1 t, . . . , z n t) converges, as a series in t, for all z ∈ C n+1 . This can be interpreted as a formal analog of Hartogs' theorem on separate analyticity. Because a divergent power series still may converge in certain directions, it is natural and desirable to consider the set of all z ∈ C n+1 for which f z converges. Since f z (t) converges if and only if f w (t) converges for all w ∈ C n+1 on the affine line through z, ignoring the trivial case z = 0, the set of directions along which f converges can be identified with a subset of P n . The convergence set Conv(f ) of a divergent power series f is defined to be the set of all directions ξ ∈ P n such that f z (t) is convergent for some z ∈ π −1 (ξ ), where π : C n+1 \{0} → P n is the natural projection. For the case n = 1, Lelong [9] proved that the convergence set of a divergent series f (x 1 , x 2 ) is an F σ polar set (i.e. a countable union of closed sets of vanishing logarithmic capacity) in P 1 , and moreover, every F σ polar subset of P 1 is contained in the convergence set of a divergent series f (x 1 , x 2 ). The optimal result was later obtained by Sathaye (see [16]) who showed that the class of convergence sets of divergent power series f (x 1 , x 2 ) is precisely the class of F σ polar sets in P 1 . To study the collection Conv(P n ) of convergence sets of divergent series in higher dimensions we consider the class PSH ω (P n ) of ω-plurisubharmonic functions on P n with respect to the form ω := dd c log |Z| on P n . We show that Conv(P n ) contains projective hulls of
AbstractThe convergence set of a divergent formal power series f (x 0 , . . . , x n ) is the set of all "directions" ξ ∈ P n along which f is absolutely convergent. We prove that every countable union of closed complete pluripolar sets in P n is the convergence set of some divergent series f. The (affine) convergence sets of formal power series with polynomial coefficients are also studied. The higher-dimensional analogs of the results of Sathaye