COSMOLOGICAL IMPLICATIONS OF RADIATIVELY GENERATED AXION SCALE

We study cosmological implications of supersymmetric axion models in w hich the axion scale is generated radiatively. Such models lead to the so-called thermal inflation and subsequent reheating should be constr ained not to yield to a too large axion energy density at the time of nucleosynthesis. We examine how plausible it is that this nucleosynthe sis constraint is satisfied for both hadronic and Dine-Fischler-Sredni cki-Zhitnitskii type axion models. Baryogenesis and the possibility fo r raising up the cosmological upper bound on the axion scale in therma l inflation scenario are also discussed. (C) 1997 Elsevier Science B.V .