Quantum generation of Schwarzschild-de Sitter (Nariai) black holes in   effective dilaton-Maxwell gravity
  Dilaton coupled electromagnetic field is essential element of low-energy string effective action or it may be considered as result of spherical compactification of Maxwell theory in higher dimensions. The large $N$ and large curvature effective action for $N$ dilaton coupled vectors is calculated. Adding such quantum correction to classical dilaton gravity action we show that effective dilaton-Maxwell gravity under consideration may generate Schwarzschild-de Sitter black holes (SdS BHs) with constant dilaton as solutions of the theory. That suggests a mechanism (alternative to BHs production) for quantum generation of SdS BHs in early universe (actually, for quantum creation of inflationary Universe) due to back-reaction of dilaton coupled matter. The possibility of proliferation of anti-de Sitter space is briefly discussed. 
Andrei A. Bytsenko, Shin'ichi Nojiri, Sergei D. Odintsov