Achievement sets of conditionally convergent series
  Considering the sets of subsums of series (or achievement sets) we show that for conditionally convergent series the multidimensional case is much more complicated than that of the real line. Although we are far from the full topological classification of such sets, we present many surprising examples and catch the ideas standing behind them in general theorems. 
Artur Bartoszewicz, Szymon G{\l}ab, Jacek Marchwicki
math.FA