Polynomial hierarchy, Betti numbers and a real analogue of Toda's theorem

Saugata Basu Thierry Zell Polynomial hierarchy, Betti numbers and a real analogue of Toda's theorem http://arxiv.org/abs/0812.1200 2008 CoRR abs/0812.1200 db/journals/corr/corr0812.html#abs-0812-1200